Elementary School Science Quiz: Planning Fair Tests
20 questions · exam conditions
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Planning Fair TestsQuestion 1 of 20

Read about the test students are planning. Carlos will test if higher ramps make a toy car roll farther. He will try ramp heights of 2, 4, 6, 8, and 10 inches. What should students do to make sure the test is fair?

Use the same toy car, the same cardboard ramp, the same starting spot, and the same floor; only change the ramp height and measure from the ramp's end.
Use a different toy car for each height and start each car from a different place, then measure how far each one rolls.
Keep all ramps the same height, but change the floor surface each time to see which floor makes the car roll farthest.
Try each height 3 times, but also change the starting spot and the ramp material to make the test more interesting.
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Elementary School Science Quiz

Elementary School Science Quiz: Planning Fair Tests

Practice Planning Fair Tests in Elementary School Science with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Planning Fair Tests, giving you a quick way to practice the rules, question types, and explanations that matter most for Elementary School Science.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

Read about the test students are planning. Carlos will test if higher ramps make a toy car roll farther. He will try ramp heights of 2, 4, 6, 8, and 10 inches. What should students do to make sure the test is fair?

  1. Use the same toy car, the same cardboard ramp, the same starting spot, and the same floor; only change the ramp height and measure from the ramp's end. (correct answer)
  2. Use a different toy car for each height and start each car from a different place, then measure how far each one rolls.
  3. Keep all ramps the same height, but change the floor surface each time to see which floor makes the car roll farthest.
  4. Try each height 3 times, but also change the starting spot and the ramp material to make the test more interesting.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. For example, if you test ramp heights but also change the car and starting spot, you won't know if distance differences came from height or the other changes. Fair tests help you understand what really causes the results. In this scenario, students want to test if higher ramps make a toy car roll farther. To make it fair, they should keep these variables the same: toy car, ramp material, starting spot, floor surface, measurement point. The ONLY thing they should change is the ramp height. Choice A is correct because it identifies proper controls: Use the same toy car, the same cardboard ramp, the same starting spot, and the same floor; only change the ramp height and measure from the ramp's end. This makes the test fair because if all other factors stay the same, any difference in results must come from the ramp height being tested. Choice B represents changes multiple variables. Students who choose this may not understand that changing multiple things makes it impossible to know what caused the results. To help students: Create T-chart labeled "What Changes (Test Variable)" and "What Stays Same (Control Variables)." There should be only ONE item under "what changes" and multiple items (3-5) under "what stays same." Ask: "If [variable X] AND [variable Y] both change, can we tell which one caused the result?" Practice identifying: "We're testing [X], so [X] changes. Everything else must stay the same." Use formula: ONLY change [test variable]; keep [list controls] all the same.

Question 2

Read about the test students are planning. Jamal has 3 magnets and wants to see which is strongest by counting paper clips. To make it a fair test, what should he keep the same?

  1. Keep the magnet type the same, but change the paper clip size each time to see which magnet works best with different kinds of clips.
  2. Keep the paper clips the same size, pick them from the same container, hold each magnet the same distance above the clips, and count clips in a hanging chain. (correct answer)
  3. Keep everything the same so the test is fair, and then choose the magnet that looks like it can hold the most paper clips.
  4. Keep the number of paper clips different for each magnet, and hold each magnet at a different height to make sure every magnet gets a chance.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. In this scenario, students want to test which magnet is strongest by counting paper clips. To make it fair, they should keep these variables the same: paper clip size, same container, same distance above clips, and same counting method. The ONLY thing they should change is which magnet they use. Choice B is correct because it identifies proper controls: keeping paper clips the same size, picking from the same container, holding each magnet the same distance, and counting clips in a hanging chain. This makes the test fair because if all other factors stay the same, any difference in the number of clips must come from the magnet strength being tested. Choice A represents keeping test variable same. Students who choose this may confuse what should change with what should stay same. To help students: Create T-chart labeled "What Changes (Test Variable)" and "What Stays Same (Control Variables)." There should be only ONE item under "what changes" and multiple items (3-5) under "what stays same." Ask: "If magnet type AND paper clip size both change, can we tell which one caused the result?" Practice identifying: "We're testing magnet strength, so magnet type changes. Everything else must stay the same." Use formula: ONLY change magnet type; keep paper clips, distance, container, and counting method all the same.

Question 3

Read about the test students are planning. Amir will test if bigger parachutes fall slower than small ones. He will drop them from 6 feet with a clay ball. To make this a fair test, what should students keep the same?

  1. Keep the parachute size the same, but change the plastic material and the string length each time, then time how long it takes to fall.
  2. Drop each parachute from a different height and use different weights, then compare which parachute falls slowest by watching with your eyes.
  3. Keep everything the same, including parachute size, and drop all parachutes once to see if the results match.
  4. Keep the shape square, use the same plastic bag material, keep strings 10 inches long, use the same clay ball, and drop from 6 feet; only change parachute size. (correct answer)
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. For example, if you test parachute sizes but also change materials and drop heights, you won't know if falling speed differences came from size or the other changes. Fair tests help you understand what really causes the results. In this scenario, students want to test if bigger parachutes fall slower. To make it fair, they should keep these variables the same: shape, plastic material, string length, weight (clay ball), drop height. The ONLY thing they should change is the parachute size. Choice B is correct because it identifies proper controls: Keep the shape square, use the same plastic bag material, keep strings 10 inches long, use the same clay ball, and drop from 6 feet; only change parachute size. This makes the test fair because if all other factors stay the same, any difference in results must come from the size being tested. Choice A represents changes multiple variables. Students who choose this may not understand that changing multiple things makes it impossible to know what caused the results. To help students: Create T-chart labeled "What Changes (Test Variable)" and "What Stays Same (Control Variables)." There should be only ONE item under "what changes" and multiple items (3-5) under "what stays same." Ask: "If [variable X] AND [variable Y] both change, can we tell which one caused the result?" Practice identifying: "We're testing [X], so [X] changes. Everything else must stay the same." Use formula: ONLY change [test variable]; keep [list controls] all the same.

Question 4

Look at the experiment. Keisha's group will test which wrap keeps ice frozen longest: newspaper, bubble wrap, or aluminum foil. Each cup gets 4 ice cubes and 2 layers of wrap. Which describes a fair test plan?

  1. Use the same size cups, 4 ice cubes each, 2 layers of wrap, and keep all cups in the same room; only change the wrapping material and time the melting. (correct answer)
  2. Use different size cups for each wrap and put some cups in the sun and some in the shade, then see which one melts last.
  3. Keep the wrapping material the same for all cups, but change the number of ice cubes in each cup to see which stays frozen longest.
  4. Wrap each cup in any amount of material you want, keep them in different rooms, and then guess which wrap works best without timing.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. For example, if you test wrapping materials but also change cup sizes and locations, you won't know if melting differences came from the material or the other changes. Fair tests help you understand what really causes the results. In this scenario, students want to test which wrapping material keeps ice frozen longest. To make it fair, they should keep these variables the same: cup size, number of ice cubes, layers of wrap, room location. The ONLY thing they should change is the wrapping material. Choice A is correct because it identifies proper controls: Use the same size cups, 4 ice cubes each, 2 layers of wrap, and keep all cups in the same room; only change the wrapping material and time the melting. This makes the test fair because if all other factors stay the same, any difference in results must come from the material being tested. Choice B represents changes multiple variables. Students who choose this may not understand that changing multiple things makes it impossible to know what caused the results. To help students: Create T-chart labeled "What Changes (Test Variable)" and "What Stays Same (Control Variables)." There should be only ONE item under "what changes" and multiple items (3-5) under "what stays same." Ask: "If [variable X] AND [variable Y] both change, can we tell which one caused the result?" Practice identifying: "We're testing [X], so [X] changes. Everything else must stay the same." Use formula: ONLY change [test variable]; keep [list controls] all the same.

Question 5

Read about the experiment. Amir tests 3 wrapping materials to keep ice frozen. To make it fair, what should he do besides changing the material?

  1. Use different numbers of ice cubes in each cup to see which material works for big ice.
  2. Keep cup size the same, use 4 ice cubes each, use 2 layers, keep all cups in the same room, and check melting after the same amount of time. (correct answer)
  3. Put some cups near a heater and some near a window to test the materials in different places.
  4. Pick the best material by touching the cup to see which feels coldest, without timing the melt.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. In this scenario, students want to test which wrapping material keeps ice frozen longest. To make it fair, they should keep these variables the same: cup size, number of ice cubes (4), number of layers (2), room location, and timing. The ONLY thing they should change is the wrapping material. Choice B is correct because it identifies all proper controls: same cup size, same ice amount, same layers, same room, and same timing for checking. This makes the test fair because if all other factors stay the same, any difference in melting must come from the material being tested. Choice C represents doesn't control important variables by placing cups in different locations (heater vs window). Students who choose this may think testing materials in different places gives more information, not understanding that temperature differences between locations would affect melting regardless of the wrapping material. To help students: Create T-chart labeled "What Changes (Test Variable)" and "What Stays Same (Control Variables)." There should be only ONE item under "what changes" (wrapping material) and multiple items (3-5) under "what stays same" (cups, ice, layers, location, time). Ask: "If material AND location both change, can we tell which one affected melting?" Practice identifying: "We're testing wrapping materials, so material changes. Everything else must stay the same." Use formula: ONLY change wrapping material; keep cups, ice, layers, location, and timing all the same.

Question 6

Read about the test students are planning. Chen made 3 paper airplane designs to see which flies farthest. Which test plan is fair?

  1. Throw all planes from 6 feet in the gym with the same force, measure to the nose each time, and ONLY change the airplane design for each set of throws. (correct answer)
  2. Throw one plane outside on a windy day and another inside, and throw from different heights, because real flights happen in many places.
  3. Use the same plane design each time, but change how hard you throw it, so you can see what force makes a plane fly farthest.
  4. Test each design once and just guess the distance by looking, because measuring takes too long and the farthest plane is easy to see.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. In this scenario, students want to test which paper airplane design flies farthest. To make it fair, they should keep these variables the same: throwing height (6 feet), location (gym), throwing force, and measurement method (to the nose). The ONLY thing they should change is the airplane design. Choice A is correct because it identifies proper controls: throwing all planes from 6 feet in the gym with the same force, measuring to the nose each time, and ONLY changing the airplane design. This makes the test fair because if all other factors stay the same, any difference in distance must come from the design being tested. Choice B represents changes multiple variables. Students who choose this may not understand that changing multiple things makes it impossible to know what caused the results. To help students: Create T-chart labeled "What Changes (Test Variable)" and "What Stays Same (Control Variables)." There should be only ONE item under "what changes" and multiple items (3-5) under "what stays same." Ask: "If airplane design AND throwing location both change, can we tell which one caused the result?" Practice identifying: "We're testing airplane design, so airplane design changes. Everything else must stay the same." Use formula: ONLY change airplane design; keep height, location, force, and measurement all the same.

Question 7

Read about the test students are planning. Emma, Jamal, and Sofia made 3 paper airplane designs. They will throw each plane 3 times in the gym from 6 feet high and measure from the plane's nose. To make a fair test, what should they keep the same?

  1. Keep the plane designs the same, but change where you throw (gym and outside) and how hard you throw, then measure the distance once.
  2. Keep things the same and change the airplane, then see which one looks like it went farthest without measuring the distance.
  3. Throw from different heights and use different force each time, then compare which design flies farthest by measuring where each plane stops on the floor.
  4. Keep the throw height at 6 feet, throw with the same force, stay inside the gym, and measure from the nose each time; only change the plane design. (correct answer)
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. For example, if you test airplane designs but also change throwing height and location, you won't know if distance differences came from the design or the other changes. Fair tests help you understand what really causes the results. In this scenario, students want to test which paper airplane design flies farthest. To make it fair, they should keep these variables the same: throw height, throw force, location (gym), measurement point (nose). The ONLY thing they should change is the plane design. Choice B is correct because it identifies proper controls: Keep the throw height at 6 feet, throw with the same force, stay inside the gym, and measure from the nose each time; only change the plane design. This makes the test fair because if all other factors stay the same, any difference in results must come from the design being tested. Choice A represents changes multiple variables. Students who choose this may not understand that changing multiple things makes it impossible to know what caused the results. To help students: Create T-chart labeled "What Changes (Test Variable)" and "What Stays Same (Control Variables)." There should be only ONE item under "what changes" and multiple items (3-5) under "what stays same." Ask: "If [variable X] AND [variable Y] both change, can we tell which one caused the result?" Practice identifying: "We're testing [X], so [X] changes. Everything else must stay the same." Use formula: ONLY change [test variable]; keep [list controls] all the same.

Question 8

Read about the test students are planning. Marcus is comparing 3 paper airplane designs to see which flies farthest. All throws are inside the gym from 6 feet high, and each plane is thrown 3 times. What is the one thing students should change in this test?

  1. Change where you measure from each time, sometimes from the tail and sometimes from the nose, to make measuring easier.
  2. Change the airplane design, while keeping throw height, throw force, location, and measuring spot the same each time. (correct answer)
  3. Change nothing at all and throw only one plane once, then decide which design is best from that throw.
  4. Change the throw height for each plane, and also change how hard you throw, so you can see many different results.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. For example, if you test airplane designs but also change throwing height and force, you won't know if distance differences came from the design or the other changes. Fair tests help you understand what really causes the results. In this scenario, students want to test which paper airplane design flies farthest. To make it fair, they should keep these variables the same: throw height, throw force, location (gym), measuring spot. The ONLY thing they should change is the airplane design. Choice A is correct because it identifies proper test variable: Change the airplane design, while keeping throw height, throw force, location, and measuring spot the same each time. This makes the test fair because keeping these variables constant means only the design affects distance, making results reliable. Choice B represents changes multiple variables. Students who choose this may not understand that changing multiple things makes it impossible to know what caused the results. To help students: Create T-chart labeled "What Changes (Test Variable)" and "What Stays Same (Control Variables)." There should be only ONE item under "what changes" and multiple items (3-5) under "what stays same." Ask: "If [variable X] AND [variable Y] both change, can we tell which one caused the result?" Practice identifying: "We're testing [X], so [X] changes. Everything else must stay the same." Use formula: ONLY change [test variable]; keep [list controls] all the same.

Question 9

Look at the experiment. Sofia is testing if sunlight or shade helps bean plants grow taller in 2 weeks. She uses the same pots, soil, and water each day. To make the test fair, what else should she keep the same?

  1. Start all plants on the same day and use the same kind of bean plant, while only changing the plant location (sunny window or shady corner). (correct answer)
  2. Use different kinds of plants and different amounts of soil, while also changing the location, so the test has more choices.
  3. Keep the location the same for all plants, but change the water amount each day and compare which plants grow taller.
  4. Keep everything the same, but do not measure the plants, because measuring could change how the plants grow.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. For example, if you test plant growth in sun versus shade but also change plant types and start days, you won't know if height differences came from light or the other changes. Fair tests help you understand what really causes the results. In this scenario, students want to test if sunlight or shade helps bean plants grow taller. To make it fair, they should keep these variables the same: plant type, pots, soil, water amount, start day. The ONLY thing they should change is the location (sunny or shady). Choice A is correct because it identifies proper controls: Start all plants on the same day and use the same kind of bean plant, while only changing the plant location (sunny window or shady corner). This makes the test fair because if all other factors stay the same, any difference in results must come from the location being tested. Choice B represents changes multiple variables. Students who choose this may not understand that changing multiple things makes it impossible to know what caused the results. To help students: Create T-chart labeled "What Changes (Test Variable)" and "What Stays Same (Control Variables)." There should be only ONE item under "what changes" and multiple items (3-5) under "what stays same." Ask: "If [variable X] AND [variable Y] both change, can we tell which one caused the result?" Practice identifying: "We're testing [X], so [X] changes. Everything else must stay the same." Use formula: ONLY change [test variable]; keep [list controls] all the same.

Question 10

Read about the test students are planning. Jamal will test 5 ramp heights (2 to 10 inches) to see how far one toy car rolls. To make this a fair test, what should students keep the same?

  1. Keep the car the same, keep the ramp material the same, keep the starting spot the same, and keep the floor surface the same; only change ramp height. (correct answer)
  2. Keep the ramp heights the same for every trial, but change the car each time to see which car rolls the farthest.
  3. Change the ramp height and the floor surface at the same time, then measure from different spots to get more data.
  4. Keep things the same, but do not say what things, and then guess the distance instead of measuring it.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. For example, if you test ramp heights but also change the car and floor surface, you won't know if distance differences came from height or the other changes. Fair tests help you understand what really causes the results. In this scenario, students want to test if higher ramps make a toy car roll farther. To make it fair, they should keep these variables the same: toy car, ramp material, starting spot, floor surface. The ONLY thing they should change is the ramp height. Choice A is correct because it identifies proper controls: Keep the car the same, keep the ramp material the same, keep the starting spot the same, and keep the floor surface the same; only change ramp height. This makes the test fair because if all other factors stay the same, any difference in results must come from the height being tested. Choice C represents changes multiple variables. Students who choose this may not understand that changing multiple things makes it impossible to know what caused the results. To help students: Create T-chart labeled "What Changes (Test Variable)" and "What Stays Same (Control Variables)." There should be only ONE item under "what changes" and multiple items (3-5) under "what stays same." Ask: "If [variable X] AND [variable Y] both change, can we tell which one caused the result?" Practice identifying: "We're testing [X], so [X] changes. Everything else must stay the same." Use formula: ONLY change [test variable]; keep [list controls] all the same.

Question 11

Look at the experiment. Carlos has 6 bean plants to test if plants grow better in sunlight or shade for 2 weeks. He will use the same pots, same soil, and water each plant the same each day. Why is it important to keep the water amount the same?

  1. So the sunlight plants will grow faster than the shade plants on purpose.
  2. So only the light place (sun or shade) can cause changes in growth, not extra water. (correct answer)
  3. So the plants will look nicer in the classroom and be easier to draw.
  4. So the test will be fair because plants don't need water to grow.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. For example, if you test airplane designs but also change throwing height and location, you won't know if distance differences came from the design or the other changes. Fair tests help you understand what really causes the results. In this scenario, students want to test if plants grow better in sunlight or shade. To make it fair, they should keep these variables the same: pots, soil, water amount each day, and measurement after 2 weeks. The ONLY thing they should change is the light place (sun or shade). Choice B is correct because it explains the importance of controlling water: 'So only the light place (sun or shade) can cause changes in growth, not extra water.' This makes the test fair because keeping water constant means only light affects growth, making results reliable. Choice C represents a misunderstanding of fair testing. Students who choose this may think fair test just means being nice to everyone rather than controlling variables. To help students: Create T-chart labeled 'What Changes (Test Variable)' and 'What Stays Same (Control Variables).' There should be only ONE item under 'what changes' and multiple items (3-5) under 'what stays same.' Ask: 'If [variable X] AND [variable Y] both change, can we tell which one caused the result?' Practice identifying: 'We're testing [X], so [X] changes. Everything else must stay the same.' Use formula: ONLY change [test variable]; keep [list controls] all the same.

Question 12

Read about the test students are planning. Yuki will compare 3 paper airplane designs to see which flies farthest. She will throw them 3 times each from 6 feet in the gym. To make this a fair test, what should Yuki keep the same?

  1. Keep the airplane design the same and change the throwing height from 3 feet to 6 feet to 9 feet.
  2. Keep the gym, throwing height of 6 feet, throwing force, and how you measure (to the nose) the same; only change the plane design and throw each 3 times. (correct answer)
  3. Keep the force different for each plane so you can help each design fly its farthest.
  4. Keep everything the same, but don't measure where the plane lands because you can just guess.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. For example, if you test airplane designs but also change throwing height and location, you won't know if distance differences came from the design or the other changes. Fair tests help you understand what really causes the results. In this scenario, students want to test which paper airplane design flies farthest. To make it fair, they should keep these variables the same: location in gym, throwing height of 6 feet, throwing force, measurement to the nose, and throw each 3 times. The ONLY thing they should change is the airplane design. Choice B is correct because it identifies proper controls: 'Keep the gym, throwing height of 6 feet, throwing force, and how you measure (to the nose) the same; only change the plane design and throw each 3 times.' This makes the test fair because if all other factors stay the same, any difference in results must come from the design being tested. Choice A represents keeps test variable same. Students who choose this may confuse what should change with what should stay same. To help students: Create T-chart labeled 'What Changes (Test Variable)' and 'What Stays Same (Control Variables).' There should be only ONE item under 'what changes' and multiple items (3-5) under 'what stays same.' Ask: 'If [variable X] AND [variable Y] both change, can we tell which one caused the result?' Practice identifying: 'We're testing [X], so [X] changes. Everything else must stay the same.' Use formula: ONLY change [test variable]; keep [list controls] all the same.

Question 13

Read about the test students are planning. Keisha will test 3 magnets by counting how many same-size paper clips each magnet can pick up. She will hold each magnet the same distance above the clips and try each magnet 3 times. What should Keisha do to make sure her test is fair?

  1. Keep the same paper clips, same distance above the clips, and count clips in a chain; only change the magnet and test each one 3 times. (correct answer)
  2. Use different sizes of paper clips for each magnet, because stronger magnets should lift bigger clips.
  3. Hold each magnet at a different height and pick paper clips from different containers to save time.
  4. Keep the magnets the same and only change the number of times you count the paper clips.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. For example, if you test airplane designs but also change throwing height and location, you won't know if distance differences came from the design or the other changes. Fair tests help you understand what really causes the results. In this scenario, students want to test which magnet picks up the most paper clips. To make it fair, they should keep these variables the same: paper clip size, distance above clips, counting clips in a chain, and test each 3 times. The ONLY thing they should change is the magnet. Choice B is correct because it identifies proper controls: 'Keep the same paper clips, same distance above the clips, and count clips in a chain; only change the magnet and test each one 3 times.' This makes the test fair because if all other factors stay the same, any difference in results must come from the magnet being tested. Choice A represents changes multiple variables. Students who choose this may not understand that changing multiple things makes it impossible to know what caused the results. To help students: Create T-chart labeled 'What Changes (Test Variable)' and 'What Stays Same (Control Variables).' There should be only ONE item under 'what changes' and multiple items (3-5) under 'what stays same.' Ask: 'If [variable X] AND [variable Y] both change, can we tell which one caused the result?' Practice identifying: 'We're testing [X], so [X] changes. Everything else must stay the same.' Use formula: ONLY change [test variable]; keep [list controls] all the same.

Question 14

Look at the experiment. Amir is testing ramp height (2 to 10 inches) to see how far a toy car rolls. He wants to measure from the bottom of the ramp to where the car stops. Which variable should Amir change to test his question?

  1. Change the starting position on the ramp each time, but keep the ramp height the same.
  2. Change the toy car each time and use a different floor so the car can roll better.
  3. Change the ramp height only; keep the same car, same ramp, same starting spot, and same floor, and measure from the bottom of the ramp each time. (correct answer)
  4. Change where you measure from and change the car's wheels, but keep the ramp height the same.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. For example, if you test airplane designs but also change throwing height and location, you won't know if distance differences came from the design or the other changes. Fair tests help you understand what really causes the results. In this scenario, students want to test if higher ramps make a toy car roll farther. To make it fair, they should keep these variables the same: toy car, ramp material, starting spot, floor surface, and measurement from bottom of ramp. The ONLY thing they should change is the ramp height. Choice B is correct because it identifies changing only the ramp height while keeping controls constant: 'Change the ramp height only; keep the same car, same ramp, same starting spot, and same floor, and measure from the bottom of the ramp each time.' This makes the test fair because keeping these variables constant means only the height affects distance, making results reliable. Choice A represents changes multiple variables. Students who choose this may not understand that changing multiple things makes it impossible to know what caused the results. To help students: Create T-chart labeled 'What Changes (Test Variable)' and 'What Stays Same (Control Variables).' There should be only ONE item under 'what changes' and multiple items (3-5) under 'what stays same.' Ask: 'If [variable X] AND [variable Y] both change, can we tell which one caused the result?' Practice identifying: 'We're testing [X], so [X] changes. Everything else must stay the same.' Use formula: ONLY change [test variable]; keep [list controls] all the same.

Question 15

Read about the test students are planning. Maya will wrap cups of ice to see what keeps ice frozen longest: newspaper, bubble wrap, or aluminum foil. Each cup will have 4 ice cubes, 2 layers of material, and stay in the same room. What is the one thing Maya should change?

  1. Change the number of ice cubes in each cup so you can see which one melts first.
  2. Change the room each cup sits in so some cups are warmer and some are cooler.
  3. Keep the wrapping material the same on all cups and only change how many layers you use.
  4. Change the wrapping material only; keep cup size, 4 ice cubes, 2 layers, and the same room, and check which cup has ice left after the same time. (correct answer)
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. For example, if you test airplane designs but also change throwing height and location, you won't know if distance differences came from the design or the other changes. Fair tests help you understand what really causes the results. In this scenario, students want to test which wrapping material keeps ice frozen longest. To make it fair, they should keep these variables the same: cup size, 4 ice cubes, 2 layers, same room, and check after the same time. The ONLY thing they should change is the wrapping material. Choice B is correct because it identifies changing only the material while keeping controls constant: 'Change the wrapping material only; keep cup size, 4 ice cubes, 2 layers, and the same room, and check which cup has ice left after the same time.' This makes the test fair because if all other factors stay the same, any difference in results must come from the material being tested. Choice C represents changes multiple variables. Students who choose this may confuse what should change with what should stay same. To help students: Create T-chart labeled 'What Changes (Test Variable)' and 'What Stays Same (Control Variables).' There should be only ONE item under 'what changes' and multiple items (3-5) under 'what stays same.' Ask: 'If [variable X] AND [variable Y] both change, can we tell which one caused the result?' Practice identifying: 'We're testing [X], so [X] changes. Everything else must stay the same.' Use formula: ONLY change [test variable]; keep [list controls] all the same.

Question 16

Read about the test students are planning. Emma made 3 paper airplane designs and wants to see which flies farthest in the gym. Each plane will be thrown from 6 feet, with the same force, and measured to the nose. Which plan is a fair test?

  1. Throw all planes from 6 feet in the gym with the same force, measure to the nose, and change only the airplane design; throw each design 3 times. (correct answer)
  2. Test one plane outside on a windy day and another inside, then compare the distances to see which design is best.
  3. Change the airplane design and also change how hard you throw each time to help each plane do its best.
  4. Keep the airplane designs the same, but throw them from 3 feet, 6 feet, and 9 feet to see what happens.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. For example, if you test airplane designs but also change throwing height and location, you won't know if distance differences came from the design or the other changes. Fair tests help you understand what really causes the results. In this scenario, students want to test which paper airplane design flies farthest. To make it fair, they should keep these variables the same: throwing height of 6 feet, location in the gym, throwing force, measurement to the nose, and throw each 3 times. The ONLY thing they should change is the airplane design. Choice A is correct because it identifies proper controls and the test variable: 'Throw all planes from 6 feet in the gym with the same force, measure to the nose, and change only the airplane design; throw each design 3 times.' This makes the test fair because if all other factors stay the same, any difference in results must come from the design being tested. Choice B represents doesn't control important variables. Students who choose this may not understand that changing multiple things makes it impossible to know what caused the results. To help students: Create T-chart labeled 'What Changes (Test Variable)' and 'What Stays Same (Control Variables).' There should be only ONE item under 'what changes' and multiple items (3-5) under 'what stays same.' Ask: 'If [variable X] AND [variable Y] both change, can we tell which one caused the result?' Practice identifying: 'We're testing [X], so [X] changes. Everything else must stay the same.' Use formula: ONLY change [test variable]; keep [list controls] all the same.

Question 17

Read about the test students are planning. Jamal and Sofia will test 3 parachute sizes (8, 12, 16 inches) by dropping them from 6 feet with a clay ball. They will use the same plastic, square shape, and 10-inch strings, and time each drop 3 times. To make this a fair test, what should they change?

  1. Change the parachute size only; keep plastic material, square shape, 10-inch strings, clay ball weight, drop height of 6 feet, and time each drop 3 times. (correct answer)
  2. Change the parachute size and also use different string lengths so the parachutes open better; keep the drop height the same and time each drop.
  3. Keep the parachute size the same each time, but change the plastic material and the clay ball weight to see which falls slowest.
  4. Drop the parachutes from different heights and in different places, then time them to see which one is best.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. For example, if you test airplane designs but also change throwing height and location, you won't know if distance differences came from the design or the other changes. Fair tests help you understand what really causes the results. In this scenario, students want to test which parachute size makes it fall slowest. To make it fair, they should keep these variables the same: plastic material, square shape, 10-inch strings, clay ball weight, drop height of 6 feet, and time each drop 3 times. The ONLY thing they should change is the parachute size. Choice A is correct because it identifies changing only the parachute size while keeping all other variables constant: 'Change the parachute size only; keep plastic material, square shape, 10-inch strings, clay ball weight, drop height of 6 feet, and time each drop 3 times.' This makes the test fair because if all other factors stay the same, any difference in results must come from the size being tested. Choice B represents changes multiple variables. Students who choose this may not understand that changing multiple things makes it impossible to know what caused the results. To help students: Create T-chart labeled 'What Changes (Test Variable)' and 'What Stays Same (Control Variables).' There should be only ONE item under 'what changes' and multiple items (3-5) under 'what stays same.' Ask: 'If [variable X] AND [variable Y] both change, can we tell which one caused the result?' Practice identifying: 'We're testing [X], so [X] changes. Everything else must stay the same.' Use formula: ONLY change [test variable]; keep [list controls] all the same.

Question 18

Read about the test students are planning. Sofia has 6 bean plants to test sunlight vs shade for 2 weeks. She will use the same bean seeds, same pot size, same soil amount, and same water each day. What is the one thing she should change?

  1. Change the pot size and soil amount, but keep the light the same for all plants.
  2. Change only where the plants are placed (sunny window or shady corner); keep seeds, pots, soil, water, and start day the same, then measure growth after 2 weeks. (correct answer)
  3. Change the type of plant for each pot, because different plants grow at different speeds.
  4. Change the amount of water each day so some plants get more and some get less.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. For example, if you test airplane designs but also change throwing height and location, you won't know if distance differences came from the design or the other changes. Fair tests help you understand what really causes the results. In this scenario, students want to test if plants grow better in sunlight or shade. To make it fair, they should keep these variables the same: bean seeds, pot size, soil amount, water each day, and start day, then measure after 2 weeks. The ONLY thing they should change is where the plants are placed (sunny window or shady corner). Choice C is correct because it identifies changing only the light placement while keeping controls constant: 'Change only where the plants are placed (sunny window or shady corner); keep seeds, pots, soil, water, and start day the same, then measure growth after 2 weeks.' This makes the test fair because if all other factors stay the same, any difference in results must come from the light being tested. Choice A represents changes multiple variables. Students who choose this may not understand that changing multiple things makes it impossible to know what caused the results. To help students: Create T-chart labeled 'What Changes (Test Variable)' and 'What Stays Same (Control Variables).' There should be only ONE item under 'what changes' and multiple items (3-5) under 'what stays same.' Ask: 'If [variable X] AND [variable Y] both change, can we tell which one caused the result?' Practice identifying: 'We're testing [X], so [X] changes. Everything else must stay the same.' Use formula: ONLY change [test variable]; keep [list controls] all the same.

Question 19

Look at the experiment. Marcus is testing which material keeps ice frozen longest: newspaper, bubble wrap, or foil. Each cup has 4 ice cubes and 2 layers of wrap in the same room. Which test plan is fair for comparing materials?

  1. Wrap cups with different materials, but use 2 ice cubes in some cups and 6 in others to see which lasts.
  2. Use the same cups, 4 ice cubes, 2 layers, and same room; only change the material and check each cup after the same amount of time. (correct answer)
  3. Put foil cups in the freezer and newspaper cups on a sunny windowsill to speed up the test.
  4. Keep the wrapping material the same on all cups and only change the cup size to compare results.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. For example, if you test airplane designs but also change throwing height and location, you won't know if distance differences came from the design or the other changes. Fair tests help you understand what really causes the results. In this scenario, students want to test which material keeps ice frozen longest. To make it fair, they should keep these variables the same: cups, 4 ice cubes, 2 layers, same room, and check after same time. The ONLY thing they should change is the wrapping material. Choice B is correct because it identifies proper controls and the test variable: 'Use the same cups, 4 ice cubes, 2 layers, and same room; only change the material and check each cup after the same amount of time.' This makes the test fair because if all other factors stay the same, any difference in results must come from the material being tested. Choice A represents changes multiple variables. Students who choose this may not understand that changing multiple things makes it impossible to know what caused the results. To help students: Create T-chart labeled 'What Changes (Test Variable)' and 'What Stays Same (Control Variables).' There should be only ONE item under 'what changes' and multiple items (3-5) under 'what stays same.' Ask: 'If [variable X] AND [variable Y] both change, can we tell which one caused the result?' Practice identifying: 'We're testing [X], so [X] changes. Everything else must stay the same.' Use formula: ONLY change [test variable]; keep [list controls] all the same.

Question 20

Read about the test students are planning. Jamal made 3 paper airplane designs and wants to see which flies farthest. To make a fair test, what should he keep the same?

  1. Throw each plane from 6 feet in the gym, use the same throwing force, and measure to the nose each time; ONLY change the airplane design. (correct answer)
  2. Try different airplane designs and also throw some from 4 feet and some from 6 feet to see which one works best.
  3. Keep the airplane design the same each time, but change how hard you throw it to see what makes it fly far.
  4. Throw the planes and keep things the same, then pick the one that looks like it went farthest without measuring.
Explanation: This question tests planning fair tests with controlled variables (NGSS 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved). A fair test means changing only ONE thing (the test variable) while keeping everything else the same (control variables). If you change multiple things at once, you can't tell which change caused the results. In this scenario, students want to test which paper airplane design flies farthest. To make it fair, they should keep these variables the same: throwing height (6 feet), throwing force, location (gym), and measurement method (to the nose). The ONLY thing they should change is the airplane design. Choice A is correct because it identifies proper controls: same height, same force, same location, and same measurement point, while only changing the design. This makes the test fair because if all other factors stay the same, any difference in flight distance must come from the design being tested. Choice B represents changing multiple variables by varying both design and throwing height. Students who choose this may not understand that changing multiple things makes it impossible to know whether the design or the height caused different results. To help students: Create T-chart labeled "What Changes (Test Variable)" and "What Stays Same (Control Variables)." There should be only ONE item under "what changes" (airplane design) and multiple items (3-5) under "what stays same" (height, force, location, measurement). Ask: "If design AND height both change, can we tell which one caused the result?" Practice identifying: "We're testing airplane design, so design changes. Everything else must stay the same." Use formula: ONLY change airplane design; keep height, force, location, and measurement all the same.