← Add and subtract 3-digit numbers left to right lesson New set →

3-Digit Mental Addition and Subtraction Worksheet

Mental maths lesson 20: Add and subtract 3-digit numbers left to right · Set 853 · 40 questions
TalentJR

How to do it in your head (Hundreds first): Keep the first number as it is and split the second into hundreds, tens and ones. Add (or take away) the hundreds first, then the tens. Finish with the ones — bridge through a ten if you need to.

NameDateTime takenScore ___ / 40
  1. 1.596 − 288 =
  2. 2.631 + 501 =
  3. 3.777 + 334 =
  4. 4.480 + 159 =
  5. 5.491 − 384 =
  6. 6.906 − 343 =
  7. 7.670 − 237 =
  8. 8.172 + 198 =
  9. 9.700 − 548 =
  10. 10.462 + 201 =
  11. 11.762 + 553 =
  12. 12.776 + 554 =
  13. 13.660 + 463 =
  14. 14.865 − 574 =
  15. 15.180 + 408 =
  16. 16.207 + 595 =
  17. 17.740 − 191 =
  18. 18.562 + 513 =
  19. 19.477 − 115 =
  20. 20.546 + 491 =
  21. 21.415 − 295 =
  22. 22.971 − 508 =
  23. 23.491 + 149 =
  24. 24.363 + 494 =
  25. 25.536 − 351 =
  26. 26.129 + 378 =
  27. 27.501 − 391 =
  28. 28.349 + 138 =
  29. 29.950 − 175 =
  30. 30.517 + 435 =
  31. 31.331 + 113 =
  32. 32.880 − 452 =
  33. 33.636 + 273 =
  34. 34.715 − 407 =
  35. 35.295 + 348 =
  36. 36.752 + 551 =
  37. 37.577 + 591 =
  38. 38.771 − 354 =
  39. 39.257 + 297 =
  40. 40.583 + 254 =

Answer key

  1. 308
  2. 1132
  3. 1111
  4. 639
  5. 107
  6. 563
  7. 433
  8. 370
  9. 152
  10. 663
  11. 1315
  12. 1330
  13. 1123
  14. 291
  15. 588
  16. 802
  17. 549
  18. 1075
  19. 362
  20. 1037
  21. 120
  22. 463
  23. 640
  24. 857
  25. 185
  26. 507
  27. 110
  28. 487
  29. 775
  30. 952
  31. 444
  32. 428
  33. 909
  34. 308
  35. 643
  36. 1303
  37. 1168
  38. 417
  39. 554
  40. 837

Free mental maths lessons, practice and worksheets at talentjr.in/mental-maths