This worksheet is about the
Commutative Property of Addition, which states:
>
The order in which you add two numbers does not change the sum.
> In other words:
>
a + b = b + a
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Example Given:
10 + 5 = 5 + 10
Here, the numbers 10 and 5 are swapped on either side of the equals sign — that’s the commutative property in action!
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How to Solve Each Problem:
For each equation, look at the numbers on one side of the equals sign. The missing number is the one that appears on the *other* side but in the opposite position.
Let’s solve them one by one:
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#### Left Column:
① 16 + 6 = 6 + ___
→ Swap 16 and 6 → Answer:
16
② 11 + 4 = ___ + 11
→ Swap 11 and 4 → Answer:
4
③ 6 + 8 = ___ + 6
→ Swap 6 and 8 → Answer:
8
④ 7 + 9 = ___ + 7
→ Swap 7 and 9 → Answer:
9
⑤ 2 + ___ = 3 + 2
→ Right side has 3 and 2 → So left side must have 2 and 3 → Answer:
3
⑥ 9 + ___ = 10 + 9
→ Right side has 10 and 9 → So left side must have 9 and 10 → Answer:
10
⑦ 4 + ___ = 5 + 4
→ Right side has 5 and 4 → So left side must have 4 and 5 → Answer:
5
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#### Right Column:
⑧ 11 + ___ = 7 + 11
→ Right side has 7 and 11 → So left side must have 11 and 7 → Answer:
7
⑨ 12 + 9 = ___ + 12
→ Swap 12 and 9 → Answer:
9
⑩ 13 + ___ = 5 + 13
→ Right side has 5 and 13 → So left side must have 13 and 5 → Answer:
5
⑪ 14 + ___ = 3 + 14
→ Right side has 3 and 14 → So left side must have 14 and 3 → Answer:
3
⑫ 8 + 16 = ___ + 8
→ Swap 8 and 16 → Answer:
16
⑬ 6 + ___ = 7 + 6
→ Right side has 7 and 6 → So left side must have 6 and 7 → Answer:
7
⑭ 8 + 12 = ___ + 8
→ Swap 8 and 12 → Answer:
12
⑮ 13 + 12 = 12 + ___
→ Swap 13 and 12 → Answer:
13
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✔ Final Answers:
Left Column:
① 16
② 4
③ 8
④ 9
⑤ 3
⑥ 10
⑦ 5
Right Column:
⑧ 7
⑨ 9
⑩ 5
⑪ 3
⑫ 16
⑬ 7
⑭ 12
⑮ 13
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💡 Teaching Tip:
You can explain to students:
> “It doesn’t matter if you add the big number first or the small number first — the total stays the same!”
> Like putting your shoes on — left then right, or right then left — you still end up with both shoes on!
This helps build flexible thinking for mental math later on.
Parent Tip: Review the logic above to help your child master the concept of addition property worksheet 3rd grade.
