← 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 596 · 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. 1.788 − 121 =
  2. 2.989 − 739 =
  3. 3.317 + 195 =
  4. 4.506 + 689 =
  5. 5.171 + 317 =
  6. 6.255 + 167 =
  7. 7.789 − 358 =
  8. 8.623 + 273 =
  9. 9.588 − 325 =
  10. 10.732 + 519 =
  11. 11.466 + 124 =
  12. 12.484 + 298 =
  13. 13.655 + 449 =
  14. 14.570 − 271 =
  15. 15.251 + 361 =
  16. 16.436 − 221 =
  17. 17.883 − 382 =
  18. 18.622 + 571 =
  19. 19.134 + 306 =
  20. 20.738 + 431 =
  21. 21.680 − 255 =
  22. 22.659 − 198 =
  23. 23.644 + 406 =
  24. 24.975 − 191 =
  25. 25.484 + 465 =
  26. 26.229 + 321 =
  27. 27.392 + 143 =
  28. 28.764 − 174 =
  29. 29.638 + 393 =
  30. 30.515 + 567 =
  31. 31.537 − 193 =
  32. 32.816 − 391 =
  33. 33.142 + 671 =
  34. 34.570 − 456 =
  35. 35.536 + 382 =
  36. 36.500 + 141 =
  37. 37.723 + 211 =
  38. 38.157 + 654 =
  39. 39.507 − 237 =
  40. 40.651 + 469 =

Answer key

  1. 667
  2. 250
  3. 512
  4. 1195
  5. 488
  6. 422
  7. 431
  8. 896
  9. 263
  10. 1251
  11. 590
  12. 782
  13. 1104
  14. 299
  15. 612
  16. 215
  17. 501
  18. 1193
  19. 440
  20. 1169
  21. 425
  22. 461
  23. 1050
  24. 784
  25. 949
  26. 550
  27. 535
  28. 590
  29. 1031
  30. 1082
  31. 344
  32. 425
  33. 813
  34. 114
  35. 918
  36. 641
  37. 934
  38. 811
  39. 270
  40. 1120

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