3 digit addition - Worksheet No.4 | Worksheets | Math Center - Free Printable

Let’s solve each addition problem step by step. We’ll add the numbers column by column, starting from the right (ones place), then tens, then hundreds. If a column adds up to 10 or more, we carry over to the next column.

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First Row:

1. 273 + 521
- Ones: 3 + 1 = 4
- Tens: 7 + 2 = 9
- Hundreds: 2 + 5 = 7
→ 794

2. 398 + 501
- Ones: 8 + 1 = 9
- Tens: 9 + 0 = 9
- Hundreds: 3 + 5 = 8
→ 899

3. 475 + 324
- Ones: 5 + 4 = 9
- Tens: 7 + 2 = 9
- Hundreds: 4 + 3 = 7
→ 799

4. 703 + 294
- Ones: 3 + 4 = 7
- Tens: 0 + 9 = 9
- Hundreds: 7 + 2 = 9
→ 997

5. 508 + 121
- Ones: 8 + 1 = 9
- Tens: 0 + 2 = 2
- Hundreds: 5 + 1 = 6
→ 629

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Second Row:

6. 572 + 118
- Ones: 2 + 8 = 10 → write 0, carry 1
- Tens: 7 + 1 + 1 (carry) = 9
- Hundreds: 5 + 1 = 6
→ 690

7. 388 + 402
- Ones: 8 + 2 = 10 → write 0, carry 1
- Tens: 8 + 0 + 1 = 9
- Hundreds: 3 + 4 = 7
→ 790

8. 527 + 233
- Ones: 7 + 3 = 10 → write 0, carry 1
- Tens: 2 + 3 + 1 = 6
- Hundreds: 5 + 2 = 7
→ 760

9. 624 + 356
- Ones: 4 + 6 = 10 → write 0, carry 1
- Tens: 2 + 5 + 1 = 8
- Hundreds: 6 + 3 = 9
→ 980

10. 479 + 211
- Ones: 9 + 1 = 10 → write 0, carry 1
- Tens: 7 + 1 + 1 = 9
- Hundreds: 4 + 2 = 6
→ 690

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Third Row:

11. 372 + 128
- Ones: 2 + 8 = 10 → write 0, carry 1
- Tens: 7 + 2 + 1 = 10 → write 0, carry 1
- Hundreds: 3 + 1 + 1 = 5
→ 500

12. 475 + 235
- Ones: 5 + 5 = 10 → write 0, carry 1
- Tens: 7 + 3 + 1 = 11 → write 1, carry 1
- Hundreds: 4 + 2 + 1 = 7
→ 710

13. 548 + 242
- Ones: 8 + 2 = 10 → write 0, carry 1
- Tens: 4 + 4 + 1 = 9
- Hundreds: 5 + 2 = 7
→ 790

14. 676 + 124
- Ones: 6 + 4 = 10 → write 0, carry 1
- Tens: 7 + 2 + 1 = 10 → write 0, carry 1
- Hundreds: 6 + 1 + 1 = 8
→ 800

15. 827 + 83
- Think of 83 as 083
- Ones: 7 + 3 = 10 → write 0, carry 1
- Tens: 2 + 8 + 1 = 11 → write 1, carry 1
- Hundreds: 8 + 0 + 1 = 9
→ 910

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Fourth Row:

16. 482 + 128
- Ones: 2 + 8 = 10 → write 0, carry 1
- Tens: 8 + 2 + 1 = 11 → write 1, carry 1
- Hundreds: 4 + 1 + 1 = 6
→ 610

17. 376 + 156
- Ones: 6 + 6 = 12 → write 2, carry 1
- Tens: 7 + 5 + 1 = 13 → write 3, carry 1
- Hundreds: 3 + 1 + 1 = 5
→ 532

18. 487 + 198
- Ones: 7 + 8 = 15 → write 5, carry 1
- Tens: 8 + 9 + 1 = 18 → write 8, carry 1
- Hundreds: 4 + 1 + 1 = 6
→ 685

19. 676 + 257
- Ones: 6 + 7 = 13 → write 3, carry 1
- Tens: 7 + 5 + 1 = 13 → write 3, carry 1
- Hundreds: 6 + 2 + 1 = 9
→ 933

20. 637 + 178
- Ones: 7 + 8 = 15 → write 5, carry 1
- Tens: 3 + 7 + 1 = 11 → write 1, carry 1
- Hundreds: 6 + 1 + 1 = 8
→ 815

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Final Answer:
794, 899, 799, 997, 629,
690, 790, 760, 980, 690,
500, 710, 790, 800, 910,
610, 532, 685, 933, 815