- The sum of a number
k and 17 is 43. This is represented by the equation k + 17 = 43. What is the value of k? Answer: 26
To find the value of k, you need to isolate it. Subtract 17 from both sides of the equation: k + 17 - 17 = 43 - 17. This simplifies to k = 26.
- You buy a snack for x dollars and add three dollars. If x+3=10, what is x?
Answer: seven
This question tests solving for an unknown in a simple equation (ISEE Lower Level Mathematics Achievement). Understanding simple equations involves isolating the variable to find its value. In the scenario 'x + 3 = 10', x represents the unknown cost of the snack before adding three dollars, and solving it involves subtracting 3 from both sides. Choice A is correct because it correctly identifies x as 7 when you isolate the variable by subtracting 3 from 10 (10 - 3 = 7). Choice B (ten) incorrectly uses the total amount, Choice C (thirteen) results from adding 3 to 10, and Choice D (three) simply repeats the known value. To help students: Create a visual representation showing x dollars plus 3 more dollars equals 10 total. Emphasize checking the answer: 7 + 3 = 10 ✓.
- You have twenty stickers, and five are left after giving away x. For 20−x=5, find x.
Answer: fifteen
This question tests solving for an unknown in a simple equation (ISEE Lower Level Mathematics Achievement). Understanding simple equations involves isolating the variable to find its value. In the scenario '20 - x = 5', x represents the unknown number of stickers given away, and solving it involves finding what number subtracted from 20 equals 5. Choice B is correct because when we solve 20 - x = 5, we get x = 20 - 5 = 15. Choice A (five) incorrectly uses the number of stickers left, Choice C (twenty) uses the starting amount, and Choice D (twenty-five) results from incorrectly adding 20 + 5. To help students: Use physical stickers to demonstrate starting with 20, giving away some, and having 5 left. Verify by substitution: 20 - 15 = 5 ✓.
- A recipe calls for a certain amount of flour,
f. Sarah doubles the amount and then removes 1 cup. She ends up with 5 cups of flour. This is represented by the equation 2f - 1 = 5. How many cups of flour, f, did the original recipe call for? Answer: 3 cups
This problem tests your ability to solve linear equations by working backwards from a word problem. When you see a recipe or cooking scenario with mathematical operations, translate each step into algebraic expressions.
Let's solve the equation 2f−1=5 step by step. To isolate f, first add 1 to both sides: 2f−1+1=5+1, which gives us 2f=6. Then divide both sides by 2: f=3. We can verify this works: if the original recipe called for 3 cups, Sarah doubled it (3×2=6), then removed 1 cup (6−1=5), ending with 5 cups as stated.
Choice A (2 cups) represents solving incorrectly by subtracting 1 from 5 instead of adding: 2f=5−1=4, then f=2. Choice B (6 cups) comes from forgetting to divide by 2 after getting 2f=6. Choice C (4 cups) might result from adding 1 to the original 3 instead of following the proper algebraic steps, or from misreading the problem setup.
The correct answer is D (3 cups).
Remember this strategy: when solving equations, always perform the inverse operations in reverse order of how they appear in the problem. Sarah doubled first, then subtracted 1, so you add 1 first, then divide by 2. Always check your answer by substituting back into the original equation. - Mr. Davis started with 30 pencils. After he gave some away, he had 12 left. The equation
30 - p = 12 can be used to find the number of pencils, p, he gave away. What is the value of p? Answer: 18
To solve for p in 30 - p = 12, you need to find what number subtracted from 30 equals 12. You can rearrange the equation to 30 - 12 = p. Performing the subtraction, 30 - 12 = 18. So, p = 18.
- You need 9 cups of flour. You already have 4 cups. Solve for x: x+4=9.
Answer: 5
This question tests solving for an unknown in a simple equation (ISEE Lower Level Mathematics Achievement). Understanding simple equations involves isolating the variable to find its value. In the scenario needing 9 cups of flour with 4 already, solving x + 4 = 9 involves subtracting 4 from both sides. Choice A is correct because it correctly identifies x as 5 when you isolate the variable by subtracting 4 from 9. Choice B is incorrect because it represents the total without solving. To help students: Teach strategies like balancing equations by performing the same operation on both sides. Encourage checking work by substituting values back into the original equation.
- I am thinking of a number,
x. If I divide it by 3 and then add 5, I get 11. The equation is x/3 + 5 = 11. What is the number? Answer: 18
To solve x/3 + 5 = 11, first subtract 5 from both sides: x/3 = 11 - 5, which gives x/3 = 6. To find x, multiply both sides by 3: x = 6 × 3, which means x = 18.
- A bus has
n seats. A group of passengers fills half the seats. Then, 3 more passengers get on. Now, there are 26 passengers on the bus. The equation n/2 + 3 = 26 represents this situation. What is the total number of seats, n, on the bus? Answer: 46
To solve the equation n/2 + 3 = 26, first subtract 3 from both sides: n/2 = 26 - 3, which simplifies to n/2 = 23. This means that half the number of seats is 23. To find the total number of seats, n, multiply 23 by 2: n = 23 × 2 = 46. The bus has 46 seats.
- Tia wants 20 dollars saved. She needs 5 more. If 20−x=5, find x.
Answer: 15
This question tests solving for an unknown in a simple equation (ISEE Lower Level Mathematics Achievement). Understanding simple equations involves isolating the variable to find its value. In the scenario where Tia wants $20 and needs $5 more, solving 20 - x = 5 gives x as saved amount of 15. Choice B is correct because it correctly identifies x as 15 when you isolate the variable. Choice A is incorrect because it uses the needed amount directly. To help students: Teach strategies like balancing equations by performing the same operation on both sides. Encourage checking work by substituting values back into the original equation.
- You bike five miles and then x miles. If 5+x=15, what is x?
Answer: ten
This question tests solving for an unknown in a simple equation (ISEE Lower Level Mathematics Achievement). Understanding simple equations involves isolating the variable to find its value. In the scenario '5 + x = 15', x represents the unknown number of miles biked after the first five miles, and solving it involves subtracting 5 from both sides. Choice B is correct because it correctly identifies x as 10 when you isolate the variable by subtracting 5 from 15 (15 - 5 = 10). Choice A (twenty) results from adding 5 to 15, Choice C (fifteen) incorrectly uses the total distance, and Choice D (five) simply repeats the known value. To help students: Use visual aids like number lines to show how subtraction helps find the missing part. Practice with real-world contexts to make the concept more concrete and relatable.
- A baker uses 9 cups of flour. Four cups are already in the bowl. If x+4=9, find x.
Answer: 5
This question tests solving for an unknown in a simple equation (ISEE Lower Level Mathematics Achievement). Understanding simple equations involves isolating the variable to find its value. In the scenario where a baker uses 9 cups with 4 already in the bowl, solving x + 4 = 9 involves subtracting 4 from both sides. Choice C is correct because it correctly identifies x as 5 when you isolate the variable by subtracting 4 from 9. Choice A is incorrect because it uses the added amount directly. To help students: Teach strategies like balancing equations by performing the same operation on both sides. Encourage checking work by substituting values back into the original equation.
- A rectangular garden has a length of 10 feet and a perimeter of 34 feet. The formula for the perimeter is
P = 2l + 2w. For this garden, the equation is 34 = 2(10) + 2w. What is the width, w, of the garden? Answer: 7 feet
Start with the equation 34 = 2(10) + 2w. First, calculate 2(10), which is 20. The equation becomes 34 = 20 + 2w. Next, subtract 20 from both sides: 34 - 20 = 2w, which simplifies to 14 = 2w. Finally, divide by 2 to find w: 14 / 2 = 7. The width is 7 feet.
- The equation
(□ × 6) + 5 = 29 is true. What number belongs in the box? Answer: 4
Let the number in the box be n. The equation is 6n + 5 = 29. First, subtract 5 from both sides: 6n = 29 - 5, so 6n = 24. Then, divide both sides by 6: n = 24 / 6, which gives n = 4. The number 4 belongs in the box.
- Mia has ten dollars. She buys a snack for 3. Solve for x: x+3=10. What is x?
Answer: 7
This question tests solving for an unknown in a simple equation (ISEE Lower Level Mathematics Achievement). Understanding simple equations involves isolating the variable to find its value. In the scenario where Mia has ten dollars and buys a snack for $3, x represents the money left, and solving x + 3 = 10 involves subtracting 3 from both sides. Choice B is correct because it correctly identifies x as 7 when you isolate the variable by subtracting 3 from 10. Choice A is incorrect because it results from misunderstanding the equation as subtraction without isolation. To help students: Teach strategies like balancing equations by performing the same operation on both sides. Encourage checking work by substituting values back into the original equation.
- A trail is 15 miles. Pat walks 5 miles. For 5+x=15, find x.
Answer: 10
This question tests solving for an unknown in a simple equation (ISEE Lower Level Mathematics Achievement). Understanding simple equations involves isolating the variable to find its value. In the scenario of a 15-mile trail where Pat walks 5 miles, solving 5 + x = 15 involves subtracting 5 from both sides. Choice A is correct because it correctly identifies x as 10 when you isolate the variable by subtracting 5 from 15. Choice B is incorrect because it might result from subtracting incorrectly. To help students: Teach strategies like balancing equations by performing the same operation on both sides. Encourage checking work by substituting values back into the original equation.
- A group of friends shared a bag of 48 candies equally. After sharing, each friend had 6 candies. The equation
48 / n = 6 represents this situation, where n is the number of friends. How many friends were in the group? Answer: 8
To solve for n, you can rewrite the division equation as a multiplication equation: 6 × n = 48. Then, divide 48 by 6 to find n: n = 48 / 6 = 8. There were 8 friends in the group.
- A walk is 15 miles total. Jay finishes 5 miles. Solve 5+x=15 for x.
Answer: 10
This question tests solving for an unknown in a simple equation (ISEE Lower Level Mathematics Achievement). Understanding simple equations involves isolating the variable to find its value. In the scenario of a 15-mile walk where Jay finishes 5 miles, solving 5 + x = 15 involves subtracting 5 from both sides. Choice B is correct because it correctly identifies x as 10 when you isolate the variable by subtracting 5 from 15. Choice A is incorrect because it mistakes the remaining for the walked. To help students: Teach strategies like balancing equations by performing the same operation on both sides. Encourage checking work by substituting values back into the original equation.
- You have ten dollars total and spend three dollars. Solve for x: 3+x=10.
Answer: seven
This question tests solving for an unknown in a simple equation (ISEE Lower Level Mathematics Achievement). Understanding simple equations involves isolating the variable to find its value. In the scenario '3 + x = 10', x represents the unknown amount of money remaining after spending three dollars from a ten-dollar total, and solving it involves subtracting 3 from both sides. Choice A is correct because it correctly identifies x as 7 when you isolate the variable by subtracting 3 from 10 (10 - 3 = 7). Choice B (ten) incorrectly uses the total amount, Choice C (thirteen) results from adding 3 to 10, and Choice D (three) repeats the amount spent. To help students: Use play money to show spending $3 from $10 and finding what's left. Practice writing equations from word problems to strengthen the connection.
- A recipe needs 9 cups of flour total. You add 4 cups. If x+4=9, what is x?
Answer: 5
This question tests solving for an unknown in a simple equation (ISEE Lower Level Mathematics Achievement). Understanding simple equations involves isolating the variable to find its value. In the scenario of a recipe needing 9 cups of flour with 4 added, x is additional needed, and solving x + 4 = 9 involves subtracting 4 from both sides. Choice B is correct because it correctly identifies x as 5 when you isolate the variable by subtracting 4 from 9. Choice A is incorrect because it adds instead of subtracting. To help students: Teach strategies like balancing equations by performing the same operation on both sides. Encourage checking work by substituting values back into the original equation.
- In a store, you spend three dollars and x dollars. If 3+x=10, what is x?
Answer: seven
This question tests solving for an unknown in a simple equation (ISEE Lower Level Mathematics Achievement). Understanding simple equations involves isolating the variable to find its value. In the scenario '3 + x = 10', x represents the unknown amount of dollars spent in addition to three dollars, and solving it involves subtracting 3 from both sides. Choice B is correct because it correctly identifies x as 7 when you isolate the variable by subtracting 3 from 10 (10 - 3 = 7). Choice A (three) is incorrect because it simply repeats the known value, Choice C (ten) incorrectly uses the total, and Choice D (thirteen) results from adding instead of subtracting. To help students: Teach the concept of inverse operations - if the equation uses addition, use subtraction to solve. Encourage students to check their answer by substituting it back: 3 + 7 = 10 ✓.