← 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 146 · 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. 1.720 − 414 =
  2. 2.676 − 272 =
  3. 3.639 + 125 =
  4. 4.706 + 285 =
  5. 5.296 + 371 =
  6. 6.278 + 642 =
  7. 7.724 + 441 =
  8. 8.477 − 304 =
  9. 9.568 − 281 =
  10. 10.130 + 191 =
  11. 11.430 − 162 =
  12. 12.498 + 591 =
  13. 13.480 − 163 =
  14. 14.876 − 582 =
  15. 15.252 + 676 =
  16. 16.164 + 601 =
  17. 17.696 + 502 =
  18. 18.860 − 755 =
  19. 19.496 + 255 =
  20. 20.667 + 273 =
  21. 21.821 − 574 =
  22. 22.324 + 342 =
  23. 23.580 − 256 =
  24. 24.919 − 347 =
  25. 25.924 − 651 =
  26. 26.285 + 459 =
  27. 27.219 + 344 =
  28. 28.553 − 364 =
  29. 29.285 + 533 =
  30. 30.139 + 444 =
  31. 31.768 + 376 =
  32. 32.136 + 637 =
  33. 33.623 − 451 =
  34. 34.155 + 501 =
  35. 35.741 − 275 =
  36. 36.563 + 318 =
  37. 37.571 − 395 =
  38. 38.744 + 523 =
  39. 39.655 + 292 =
  40. 40.691 − 152 =

Answer key

  1. 306
  2. 404
  3. 764
  4. 991
  5. 667
  6. 920
  7. 1165
  8. 173
  9. 287
  10. 321
  11. 268
  12. 1089
  13. 317
  14. 294
  15. 928
  16. 765
  17. 1198
  18. 105
  19. 751
  20. 940
  21. 247
  22. 666
  23. 324
  24. 572
  25. 273
  26. 744
  27. 563
  28. 189
  29. 818
  30. 583
  31. 1144
  32. 773
  33. 172
  34. 656
  35. 466
  36. 881
  37. 176
  38. 1267
  39. 947
  40. 539

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