Educational worksheet teaching the associative property of addition through matching and solving addition problems.

Let’s solve each addition problem step by step. We’ll add the first two numbers, then add the third number to get the total.

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1. 3 + 7 + 4 = ?

First: 3 + 7 = 10
Then: 10 + 4 = 14

So we can write it as:
3 + 7 + 4 = 10 + 4 = 14

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2. 1 + 9 + 3 = ?

First: 1 + 9 = 10
Then: 10 + 3 = 13

So:
1 + 9 + 3 = 10 + 3 = 13

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3. 2 + 8 + 9 = ?

First: 2 + 8 = 10
Then: 10 + 9 = 19

So:
2 + 8 + 9 = 10 + 9 = 19

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4. 4 + 6 + 2 = ?

First: 4 + 6 = 10
Then: 10 + 2 = 12

So:
4 + 6 + 2 = 10 + 2 = 12

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5. 5 + 5 + 6 = ?

First: 5 + 5 = 10
Then: 10 + 6 = 16

So:
5 + 5 + 6 = 10 + 6 = 16

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Now let’s match them with the cut-out boxes at the bottom:

- 3 + 7 + 4 → matches 10 + 4
- 1 + 9 + 3 → matches 10 + 3
- 2 + 8 + 9 → matches 10 + 9
- 4 + 6 + 2 → matches 10 + 2
- 5 + 5 + 6 → matches 10 + 6

All totals are correct and matched properly.

Final Answer:
3 + 7 + 4 = 10 + 4 = 14
1 + 9 + 3 = 10 + 3 = 13
2 + 8 + 9 = 10 + 9 = 19
4 + 6 + 2 = 10 + 2 = 12
5 + 5 + 6 = 10 + 6 = 16