Addition worksheet with regrouping exercises for 3-digit numbers.

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 — and regroup (carry over) when needed.

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1. 453 + 164

- Ones: 3 + 4 = 7
- Tens: 5 + 6 = 11 → write 1, carry 1 to hundreds
- Hundreds: 4 + 1 + 1 (carry) = 6
→ 617

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2. 527 + 185

- Ones: 7 + 5 = 12 → write 2, carry 1
- Tens: 2 + 8 + 1 = 11 → write 1, carry 1
- Hundreds: 5 + 1 + 1 = 7
→ 712

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3. 358 + 236

- Ones: 8 + 6 = 14 → write 4, carry 1
- Tens: 5 + 3 + 1 = 9
- Hundreds: 3 + 2 = 5
→ 594

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4. 264 + 174

- Ones: 4 + 4 = 8
- Tens: 6 + 7 = 13 → write 3, carry 1
- Hundreds: 2 + 1 + 1 = 4
→ 438

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5. 589 + 305

- Ones: 9 + 5 = 14 → write 4, carry 1
- Tens: 8 + 0 + 1 = 9
- Hundreds: 5 + 3 = 8
→ 894

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6. 753 + 248

- Ones: 3 + 8 = 11 → write 1, carry 1
- Tens: 5 + 4 + 1 = 10 → write 0, carry 1
- Hundreds: 7 + 2 + 1 = 10 → write 0, carry 1 → thousands digit is 1
→ 1001

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7. 247 + 265

- Ones: 7 + 5 = 12 → write 2, carry 1
- Tens: 4 + 6 + 1 = 11 → write 1, carry 1
- Hundreds: 2 + 2 + 1 = 5
→ 512

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8. 422 + 396

- Ones: 2 + 6 = 8
- Tens: 2 + 9 = 11 → write 1, carry 1
- Hundreds: 4 + 3 + 1 = 8
→ 818

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9. 356 + 278

- Ones: 6 + 8 = 14 → write 4, carry 1
- Tens: 5 + 7 + 1 = 13 → write 3, carry 1
- Hundreds: 3 + 2 + 1 = 6
→ 634

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10. 169 + 164

- Ones: 9 + 4 = 13 → write 3, carry 1
- Tens: 6 + 6 + 1 = 13 → write 3, carry 1
- Hundreds: 1 + 1 + 1 = 3
→ 333

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11. 680 + 289

- Ones: 0 + 9 = 9
- Tens: 8 + 8 = 16 → write 6, carry 1
- Hundreds: 6 + 2 + 1 = 9
→ 969

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12. 413 + 469

- Ones: 3 + 9 = 12 → write 2, carry 1
- Tens: 1 + 6 + 1 = 8
- Hundreds: 4 + 4 = 8
→ 882

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13. 602 + 598

- Ones: 2 + 8 = 10 → write 0, carry 1
- Tens: 0 + 9 + 1 = 10 → write 0, carry 1
- Hundreds: 6 + 5 + 1 = 12 → write 2, carry 1 → thousands digit is 1
→ 1200

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14. 723 + 786

- Ones: 3 + 6 = 9
- Tens: 2 + 8 = 10 → write 0, carry 1
- Hundreds: 7 + 7 + 1 = 15 → write 5, carry 1 → thousands digit is 1
→ 1509

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15. 558 + 565

- Ones: 8 + 5 = 13 → write 3, carry 1
- Tens: 5 + 6 + 1 = 12 → write 2, carry 1
- Hundreds: 5 + 5 + 1 = 11 → write 1, carry 1 → thousands digit is 1
→ 1123

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16. 864 + 297

- Ones: 4 + 7 = 11 → write 1, carry 1
- Tens: 6 + 9 + 1 = 16 → write 6, carry 1
- Hundreds: 8 + 2 + 1 = 11 → write 1, carry 1 → thousands digit is 1
→ 1161

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Final Answer:

453 + 164 = 617
527 + 185 = 712
358 + 236 = 594
264 + 174 = 438
589 + 305 = 894
753 + 248 = 1001
247 + 265 = 512
422 + 396 = 818
356 + 278 = 634
169 + 164 = 333
680 + 289 = 969
413 + 469 = 882
602 + 598 = 1200
723 + 786 = 1509
558 + 565 = 1123
864 + 297 = 1161