1st Grade Math Quiz: Addition And Subtraction Fluency
20 questions · exam conditions
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Addition And Subtraction FluencyQuestion 1 of 20

Complete: 8+6=8+2+ . What number goes in the blank?

2
4
6
8
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1st Grade Math Quiz

1st Grade Math Quiz: Addition And Subtraction Fluency

Practice Addition And Subtraction Fluency in 1st Grade Math 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 Addition And Subtraction Fluency, giving you a quick way to practice the rules, question types, and explanations that matter most for 1st Grade Math.

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

Complete: 8+6=8+2+ . What number goes in the blank?

  1. 2
  2. 4 (correct answer)
  3. 6
  4. 8
Explanation: This question is really about a clever math idea: breaking numbers apart. When you see 8+6, you can split the 6 into two smaller pieces. Notice that the right side already shows 8+2+ . So the 6 has been broken into 2 and something else. Ask yourself: "2 plus what makes 6?" Since 2 + 4 = 6, the missing piece must be 4. You can double-check by adding both sides: the left side is 8+6=14, and the right side is 8+2+4 = 10+4 = 14. They match, so 4 is correct. The choice 2 is a trap because that number is already written in the problem — but 2+2 only makes 4, not the 6 you need. The choice 6 is wrong because it repeats the original number you were supposed to split; using it would give 8+2+6=16, which is too big. The choice 8 just copies the first number in the problem; 8+2+8=18 is far too large. Only 4 keeps both sides equal. A smart trick to remember: when a number gets split into parts, all the parts must add back up to the whole. Here the whole is 6, one part is 2, so the other part fills in the gap. Whenever both sides of an equal sign should match, add each side up and make sure they land on the same total.

Question 2

Complete the subtract-to-10 step: 15-7=15-5- .

  1. 1
  2. 2 (correct answer)
  3. 3
  4. 5
Explanation: This question is about the "subtract to 10" strategy, a clever way to make subtraction easier. When you subtract a number, you can break it into two smaller pieces: first subtract enough to reach a friendly number like 10, then subtract the rest. The trick is figuring out how much is "left over" after the first step. Look at the starting number, 15. To get down to 10, you subtract 5, which is why the problem already shows 15 - 5. But you were supposed to subtract 7 total, not just 5. Since you've only taken away 5 so far, you still need to subtract the rest: 7 - 5 = 2. So the blank is 2, giving you 15 - 5 - 2 = 8. And that matches, because 15 - 7 = 8 too! Now let's check the other choices. Choosing 1 is a small miscount — it would only subtract 6 total, not 7. Choosing 3 oversubtracts, taking away 8 altogether and landing on 7 instead of 8. Choosing 5 repeats the first number you already used (15 - 5) instead of finding what's left over, which would take away way too much. Here's your memory tip: the two pieces you subtract must add up to the whole number you're removing. Since 5 + 2 = 7, you know 2 is correct. Always ask, "How much more do I still need to subtract to reach my full amount?"

Question 3

Complete the making-ten step: 8+6=8+2+ .

  1. 2
  2. 4 (correct answer)
  3. 6
  4. 8
Explanation: The make-a-ten strategy is a powerful trick for adding numbers when the total goes past 10. The idea is to break one number apart so you can first build a friendly, easy-to-use 10, then add whatever is left over. Whenever you see a problem like this, ask yourself: "How much do I need to reach 10, and how much will be left?" Here you're adding 8+6. Since 8 needs just 2 more to become 10, you take those 2 from the 6. That's why the problem shows 8+2. But the 6 wasn't all used up — you only borrowed 2 of it, so 6-2=4 is left. That leftover 4 fills the blank, giving 8+2+4=10+4=14. Now look at the other choices. Picking 2 repeats the number you already moved over to make ten, but that 2 is now part of the ten, not leftover. Choosing 6 just copies the original second number, forgetting that you already used 2 of it to reach ten. Choosing 8 simply repeats the first number and ignores the strategy entirely. Only 4 correctly shows what remains of the 6 after making ten. A handy way to remember: whatever you give to make ten, you must take away from the other number. Since 8 took 2 from the 6, the 6 shrinks to 4. Practice splitting the second number into "what's needed for ten" plus "what's left," and this strategy will feel automatic.

Question 4

Use counting on to solve 9+39+3. What is the answer?​

  1. 11
  2. 12 (correct answer)
  3. 13
  4. 10
Explanation: This question tests 1st grade fluency in addition and subtraction within 20, with emphasis on strategies (CCSS.1.OA.6). Counting on is a strategy where you start from the larger number and count up by the smaller number. For example, for 9 + 3, start at 9 and count on three: 10, 11, 12. This is efficient for small addends. The problem asks to use counting on to solve 9 + 3. Choice B is correct because counting on from 9 by 3 gives 10, 11, 12. Choice A is a common error where students make a calculation error, such as starting from 8 instead of 9; this happens because keeping track of parts while combining them is cognitively demanding. To help students: Practice counting on with small numbers first; use number lines or fingers to visualize; provide daily practice with mixed strategies; help students select appropriate strategy for each problem type, like counting on for addends less than 4.

Question 5

How many apples now? Mia has 7 apples and gets 2 more; count on.

  1. 8
  2. 9 (correct answer)
  3. 10
  4. 7
Explanation: This question tests 1st grade fluency in addition and subtraction within 20, with emphasis on strategies (CCSS.1.OA.6). Counting on is a strategy for addition where you start with the larger number and count up by the smaller number. For example, for 7 + 2, start at 7 and count on two more: 8, 9, so the total is 9. The problem asks how many apples Mia has now after starting with 7 and getting 2 more, using count on. Choice B is correct because starting at 7 and counting on 2 gives 8, 9. Choice C is a common error where students make a calculation error or count on too many, getting 10; this happens because keeping track of parts while combining them is cognitively demanding. To help students: Practice counting on with concrete objects like fingers or counters; emphasize starting with the larger number; provide daily practice with mixed strategies; help students select appropriate strategy for each problem type.

Question 6

Solve 15−715-7 by decomposing to ten: 15−5−215-5-2.

  1. 9
  2. 7
  3. 8 (correct answer)
  4. 6
Explanation: This question tests 1st grade fluency in addition and subtraction within 20, with emphasis on strategies (CCSS.1.OA.6). For subtraction across 10, decompose the subtrahend to first reach 10, then subtract the rest. For 15 - 7, we think: 15 to 10 is 5, so break 7 into 5 + 2, then 15 - 7 = (15 - 5) - 2 = 10 - 2 = 8. The problem asks to solve 15 - 7 by decomposing to ten: 15 - 5 - 2. Choice C is correct because decomposing to 10: 15 - 5 - 2 = 10 - 2 = 8. Choice A is a common error where students don't decompose correctly and get a wrong answer like 9; this happens because decomposing numbers flexibly is challenging. To help students: For decomposing to 10 in subtraction, practice with many examples showing the 'get to 10 first' step; use ten-frames to visualize; provide daily practice with mixed strategies; help students select appropriate strategy for each problem type.

Question 7

Solve 6+76+7 using doubles plus 1. What is the sum?​

  1. 12
  2. 14
  3. 13 (correct answer)
  4. 11
Explanation: This question tests 1st grade fluency in addition and subtraction within 20, with emphasis on strategies (CCSS.1.OA.6). Creating equivalent sums using doubles helps with near-doubles. For 6 + 7, we recognize these are close to the double 6 + 6. We think: 6 + 7 = 6 + 6 + 1 = 12 + 1 = 13. The problem asks to solve 6 + 7 using doubles plus 1. Choice C is correct because using doubles: 6 + 7 = 6 + 6 + 1 = 12 + 1 = 13. Choice A is a common error where for near-doubles, students forget to add the +1; this happens because students may try to compute without using the strategy. To help students: For doubles, ensure all doubles facts are memorized (6+6, 7+7, 8+8, 9+9); for near-doubles, practice thinking 'double plus/minus 1'; provide daily practice with mixed strategies; help students select appropriate strategy for each problem type.

Question 8

If 8+4=128+4=12, what is 12−812-8?​

  1. 3
  2. 5
  3. 4 (correct answer)
  4. 8
Explanation: This question tests 1st grade fluency in addition and subtraction within 20, with emphasis on strategies (CCSS.1.OA.6). Fact families show the relationship between addition and subtraction. For example, if 8 + 4 = 12, then 12 - 8 = 4 and 12 - 4 = 8. The problem asks to use the fact that 8 + 4 = 12 to find 12 - 8. Choice C is correct because using the known addition fact, 12 - 8 = 4 since 8 + 4 = 12. Choice A is a common error where students use the wrong operation or make a calculation error; this happens because the connection between addition and subtraction facts must be explicitly taught. To help students: For fact families, show all four related facts together; emphasize that facts within 10 should be automatic; provide daily practice with mixed strategies; help students select appropriate strategy for each problem type.

Question 9

Create an easier sum: 9+69+6 can be 10+510+5. What is 9+69+6?

  1. 14
  2. 15 (correct answer)
  3. 16
  4. 13
Explanation: This question tests 1st grade fluency in addition and subtraction within 20, with emphasis on strategies (CCSS.1.OA.6). Creating an easier sum, like compensating, adjusts numbers to make addition simpler. For example, for 9 + 6, we can think of it as 10 + 5 by adding 1 to 9 and subtracting 1 from 6, so 10 + 5 = 15. The problem asks to create an easier sum: 9 + 6 can be 10 + 5, and find 9 + 6. Choice B is correct because 9 + 6 = 10 + 5 = 15. Choice A is a common error where students make a calculation error in compensation, getting 14; this happens because keeping track of parts while combining them is cognitively demanding. To help students: Practice compensation by adjusting pairs to make 10; use ten-frames to visualize; provide daily practice with mixed strategies; help students select appropriate strategy for each problem type.

Question 10

Solve 7+67+6 by making a ten.

  1. 12
  2. 14
  3. 13 (correct answer)
  4. 11
Explanation: Making a ten from 7 and part of 6 leaves 3 more to add, giving 7 plus 6 equals 13. 12 is one less than the correct sum. 14 is one more than the correct sum. 11 is two less than the correct sum. Only 13 correctly shows the sum of 7 and 6.

Question 11

Mia has 7 stickers and gets 6 more. Use the make-ten strategy to find how many stickers she has in all.

  1. 12
  2. 14
  3. 13 (correct answer)
  4. 11
Explanation: Mia has 7 stickers and gets 6 more, so 7 plus 6 equals 13. 12 is one less than the correct total. 14 is one more than the correct total. 11 is two less than the correct total. Only 13 correctly adds Mia's starting stickers and the new ones she received.

Question 12

To solve 15−715-7, first subtract 55: 15−5=1015-5=10. What should you subtract next?

  1. 11
  2. 22 (correct answer)
  3. 55
  4. 77
Explanation: After subtracting 5 to reach 10, there are 2 left of the original 7 still to subtract, so the next step is to subtract 2. Subtracting 1 doesn't account for all of the remaining amount. Subtracting 5 again would subtract too much, more than the original 7. Subtracting 7 again repeats the whole amount instead of just what's left. Only subtracting 2 correctly finishes taking away the full 7.

Question 13

Complete the making-ten step: 8+6=8+2+ .

  1. 2
  2. 4 (correct answer)
  3. 6
  4. 8
Explanation: The make-a-ten strategy is a clever way to add numbers when one of them is close to 10. The idea is to break apart the smaller number so you can first build a friendly, easy-to-work-with 10, then add whatever is left over. Whenever you see a problem like this, ask yourself: "How many more do I need to turn 8 into 10?" Here, you start with 8+6. To make 8 into a 10, you need to add 2 — that's why the problem already shows 8+2. But you can't just add 2 out of nowhere; you have to take that 2 from the 6. Since 6 = 2 + 4, once you use up the 2, there are 4 left. So 8+6 = 8+2+4 = 10+4 = 14. The missing number is 4. Now look at the traps. The choice 2 repeats the number already used to make the ten, but that 2 is spoken for — it can't appear twice. The choice 6 is just the original number you were adding; if you added the full 6 again, you'd be adding way too much. The choice 8 is the first number in the problem, not part of splitting the 6 at all — it's there to tempt you into grabbing a familiar number. Remember this pattern: when you split the second number to make ten, the two pieces must add back up to the original number. Here 2+4=6, which checks out perfectly.

Question 14

Solve 13−413-4 by subtracting to 10. What is the answer?​

  1. 8
  2. 10
  3. 9 (correct answer)
  4. 7
Explanation: This question tests 1st grade fluency in addition and subtraction within 20, with emphasis on strategies (CCSS.1.OA.6). For subtraction across 10, decompose the subtrahend to first reach 10, then subtract the rest. For 13 - 4, we think: 13 to 10 is 3, so break 4 into 3 + 1. Then: 13 - 4 = (13 - 3) - 1 = 10 - 1 = 9. The problem asks to solve 13 - 4 by subtracting to 10. Choice C is correct because decomposing to 10: 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9. Choice A is a common error where students don't apply the strategy systematically, such as subtracting all at once and miscounting; this happens because these strategies require multiple steps and practice. To help students: For decomposing to 10 in subtraction, practice with many examples showing the 'get to 10 first' step; use ten-frames; provide daily practice with mixed strategies; emphasize that facts within 10 should be automatic.

Question 15

If 8+4=128+4=12, what is 12−812-8? Use the related fact.

  1. 3
  2. 4 (correct answer)
  3. 8
  4. 12
Explanation: This question tests 1st grade fluency in addition and subtraction within 20, with emphasis on strategies (CCSS.1.OA.6). Using related addition and subtraction facts helps solve problems through fact families. For example, if 8 + 4 = 12, then the related subtraction is 12 - 8 = 4. The problem asks if 8 + 4 = 12, what is 12 - 8, using the related fact. Choice B is correct because using the known addition fact, 12 - 8 = 4 since 8 + 4 = 12. Choice A is a common error where students use the wrong operation or make a calculation error, getting 3; this happens because the connection between addition and subtraction facts must be explicitly taught. To help students: For fact families, show all four related facts together; emphasize that facts within 10 should be automatic (fluent); provide daily practice with mixed strategies; help students select appropriate strategy for each problem type.

Question 16

Solve 6+76+7 using doubles plus 1. What is the sum?

  1. 12
  2. 14
  3. 13 (correct answer)
  4. 11
Explanation: This question tests 1st grade fluency in addition and subtraction within 20, with emphasis on strategies (CCSS.1.OA.6). Creating equivalent sums using doubles helps with near-doubles. For 6 + 7, we recognize these are close to the double 6 + 6. We think: 6 + 7 = 6 + 6 + 1 = 12 + 1 = 13. The problem asks to solve 6 + 7 using doubles plus 1. Choice C is correct because using doubles: 6 + 7 = 6 + 6 + 1 = 12 + 1 = 13. Choice A is a common error where for near-doubles, students forget to add the +1; this happens because students may try to compute without using the strategy. To help students: For doubles, ensure all doubles facts are memorized (6+6, 7+7, 8+8, 9+9); for near-doubles, practice thinking 'double plus/minus 1'; provide daily practice with mixed strategies; help students select appropriate strategy for each problem type.

Question 17

Mia has 7 stickers and gets 6 more; make ten to find how many.​

  1. 12
  2. 14
  3. 13 (correct answer)
  4. 11
Explanation: This question tests 1st grade fluency in addition and subtraction within 20, with emphasis on strategies (CCSS.1.OA.6). The making-10 strategy helps add numbers that cross 10. To use it, decompose the second number into the amount needed to make 10, plus the remainder. For example, for 8 + 6, we think: 8 needs 2 more to make 10, so break 6 into 2 + 4. Then: 8 + 6 = 8 + (2 + 4) = (8 + 2) + 4 = 10 + 4 = 14. The problem asks to solve 7 + 6 using making ten in a word problem context. Choice C is correct because following making-10: 7 + 6 = 7 + 3 + 3 = 10 + 3 = 13. Choice A is a common error where students make a calculation error, such as forgetting to add the remainder; this happens because keeping track of parts while combining them is cognitively demanding. To help students: For making-10, explicitly teach pairs that make 10 (1+9, 2+8, 3+7, 4+6, 5+5) and practice decomposing; use ten-frames to visualize making 10; provide daily practice with mixed strategies; help students select appropriate strategy for each problem type.

Question 18

Solve 9+29+2 using counting on. Start at 9 and count 2.

  1. 10
  2. 11 (correct answer)
  3. 12
  4. 13
Explanation: This question tests 1st grade fluency in addition and subtraction within 20, with emphasis on strategies (CCSS.1.OA.6). Counting on is a strategy for addition where you start with the first number and count forward by the second number. For example, for 9 + 2, start at 9 and count: 10, 11. The problem asks to use counting on to solve 9 + 2, starting at 9 and counting 2. Choice B is correct because 9 + 2: starting at 9, count on two: 10, 11. Choice C is a common error where students make a calculation error like counting one extra to 12; this happens because students may try to compute without using the strategy systematically. To help students: Practice counting on with small numbers first; use number lines or fingers to visualize; provide daily practice with mixed strategies; emphasize that facts within 10 should be automatic (fluent).

Question 19

What is 7+87+8?

  1. 16
  2. 14
  3. 15 (correct answer)
  4. 13
Explanation: Adding 7 and 8 together gives a sum of 15. 16 is one more than the correct sum. 14 is one less than the correct sum. 13 is two less than the correct sum. Only 15 correctly shows the sum of 7 and 8.

Question 20

Solve 9+79+7 by making ten. What is the sum?

  1. 15
  2. 16 (correct answer)
  3. 17
  4. 14
Explanation: This question tests 1st grade fluency in addition and subtraction within 20, with emphasis on strategies (CCSS.1.OA.6). The making-10 strategy helps add numbers that cross 10. To use it, decompose the second number into the amount needed to make 10, plus the remainder. For example, for 8 + 6, we think: 8 needs 2 more to make 10, so break 6 into 2 + 4, then 8 + 6 = 8 + (2 + 4) = (8 + 2) + 4 = 10 + 4 = 14. The problem asks to solve 9 + 7 using the making-10 strategy. Choice B is correct because following making-10: 9 + 7 = 9 + 1 + 6 = 10 + 6 = 16. Choice A is a common error where students don't decompose correctly and get a wrong answer like adding without strategy, such as 9 + 6 = 15, forgetting the full decomposition; this happens because these strategies require multiple steps and practice. To help students: For making-10, explicitly teach pairs that make 10 (1+9, 2+8, 3+7, 4+6, 5+5) and practice decomposing; use ten-frames to visualize making 10; provide daily practice with mixed strategies; help students select appropriate strategy for each problem type.