Third Grade Addition Worksheets - Free Printable

Let’s solve each addition problem one by one. We’ll add the numbers column by column, starting from the right (ones place), then tens, then hundreds — just like we do in 3rd grade math!

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Row 1:

1. 124 + 21
Ones: 4 + 1 = 5
Tens: 2 + 2 = 4
Hundreds: 1 + 0 = 1
→ 145

2. 141 + 16
Ones: 1 + 6 = 7
Tens: 4 + 1 = 5
Hundreds: 1 + 0 = 1
→ 157

3. 167 + 26
Ones: 7 + 6 = 13 → write 3, carry 1
Tens: 6 + 2 + 1 (carry) = 9
Hundreds: 1 + 0 = 1
→ 193

4. 174 + 15
Ones: 4 + 5 = 9
Tens: 7 + 1 = 8
Hundreds: 1 + 0 = 1
→ 189

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Row 2:

5. 205 + 65
Ones: 5 + 5 = 10 → write 0, carry 1
Tens: 0 + 6 + 1 = 7
Hundreds: 2 + 0 = 2
→ 270

6. 219 + 78
Ones: 9 + 8 = 17 → write 7, carry 1
Tens: 1 + 7 + 1 = 9
Hundreds: 2 + 0 = 2
→ 297

7. 246 + 54
Ones: 6 + 4 = 10 → write 0, carry 1
Tens: 4 + 5 + 1 = 10 → write 0, carry 1
Hundreds: 2 + 0 + 1 = 3
→ 300

8. 439 + 62
Ones: 9 + 2 = 11 → write 1, carry 1
Tens: 3 + 6 + 1 = 10 → write 0, carry 1
Hundreds: 4 + 0 + 1 = 5
→ 501

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Row 3:

9. 104 + 103
Ones: 4 + 3 = 7
Tens: 0 + 0 = 0
Hundreds: 1 + 1 = 2
→ 207

10. 146 + 120
Ones: 6 + 0 = 6
Tens: 4 + 2 = 6
Hundreds: 1 + 1 = 2
→ 266

11. 174 + 147
Ones: 4 + 7 = 11 → write 1, carry 1
Tens: 7 + 4 + 1 = 12 → write 2, carry 1
Hundreds: 1 + 1 + 1 = 3
→ 321

12. 136 + 127
Ones: 6 + 7 = 13 → write 3, carry 1
Tens: 3 + 2 + 1 = 6
Hundreds: 1 + 1 = 2
→ 263

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Row 4:

13. 208 + 193
Ones: 8 + 3 = 11 → write 1, carry 1
Tens: 0 + 9 + 1 = 10 → write 0, carry 1
Hundreds: 2 + 1 + 1 = 4
→ 401

14. 615 + 310
Ones: 5 + 0 = 5
Tens: 1 + 1 = 2
Hundreds: 6 + 3 = 9
→ 925

15. 454 + 342
Ones: 4 + 2 = 6
Tens: 5 + 4 = 9
Hundreds: 4 + 3 = 7
→ 796

16. 626 + 321
Ones: 6 + 1 = 7
Tens: 2 + 2 = 4
Hundreds: 6 + 3 = 9
→ 947

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Final Answer:
145, 157, 193, 189, 270, 297, 300, 501, 207, 266, 321, 263, 401, 925, 796, 947