← 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 774 · 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. 1.467 − 147 =
  2. 2.781 − 218 =
  3. 3.784 − 434 =
  4. 4.704 + 355 =
  5. 5.532 + 452 =
  6. 6.163 + 211 =
  7. 7.470 + 121 =
  8. 8.682 + 374 =
  9. 9.439 − 261 =
  10. 10.341 + 338 =
  11. 11.888 − 717 =
  12. 12.601 + 612 =
  13. 13.739 − 246 =
  14. 14.632 − 439 =
  15. 15.651 + 624 =
  16. 16.169 + 309 =
  17. 17.506 − 228 =
  18. 18.837 − 717 =
  19. 19.571 + 399 =
  20. 20.566 − 248 =
  21. 21.605 − 348 =
  22. 22.512 − 162 =
  23. 23.577 + 117 =
  24. 24.138 + 603 =
  25. 25.576 − 157 =
  26. 26.560 − 338 =
  27. 27.191 + 561 =
  28. 28.673 − 476 =
  29. 29.692 + 348 =
  30. 30.795 − 597 =
  31. 31.705 + 345 =
  32. 32.608 + 665 =
  33. 33.348 + 431 =
  34. 34.465 − 156 =
  35. 35.644 − 131 =
  36. 36.902 − 722 =
  37. 37.482 + 604 =
  38. 38.654 + 595 =
  39. 39.399 + 431 =
  40. 40.264 + 617 =

Answer key

  1. 320
  2. 563
  3. 350
  4. 1059
  5. 984
  6. 374
  7. 591
  8. 1056
  9. 178
  10. 679
  11. 171
  12. 1213
  13. 493
  14. 193
  15. 1275
  16. 478
  17. 278
  18. 120
  19. 970
  20. 318
  21. 257
  22. 350
  23. 694
  24. 741
  25. 419
  26. 222
  27. 752
  28. 197
  29. 1040
  30. 198
  31. 1050
  32. 1273
  33. 779
  34. 309
  35. 513
  36. 180
  37. 1086
  38. 1249
  39. 830
  40. 881

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