← 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 636 · 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. 1.986 − 428 =
  2. 2.243 + 523 =
  3. 3.158 + 542 =
  4. 4.698 + 491 =
  5. 5.300 + 522 =
  6. 6.214 + 341 =
  7. 7.247 + 651 =
  8. 8.633 − 213 =
  9. 9.596 + 473 =
  10. 10.732 − 412 =
  11. 11.722 − 529 =
  12. 12.156 + 364 =
  13. 13.885 − 428 =
  14. 14.144 + 472 =
  15. 15.686 − 254 =
  16. 16.124 + 284 =
  17. 17.836 − 542 =
  18. 18.623 + 272 =
  19. 19.669 − 248 =
  20. 20.838 − 466 =
  21. 21.334 + 622 =
  22. 22.378 + 113 =
  23. 23.330 + 606 =
  24. 24.965 − 716 =
  25. 25.678 − 254 =
  26. 26.240 + 114 =
  27. 27.549 + 231 =
  28. 28.534 − 196 =
  29. 29.740 − 417 =
  30. 30.198 + 573 =
  31. 31.204 + 443 =
  32. 32.706 − 325 =
  33. 33.276 + 184 =
  34. 34.182 + 431 =
  35. 35.687 + 498 =
  36. 36.411 + 185 =
  37. 37.866 − 647 =
  38. 38.213 + 288 =
  39. 39.556 − 311 =
  40. 40.249 + 226 =

Answer key

  1. 558
  2. 766
  3. 700
  4. 1189
  5. 822
  6. 555
  7. 898
  8. 420
  9. 1069
  10. 320
  11. 193
  12. 520
  13. 457
  14. 616
  15. 432
  16. 408
  17. 294
  18. 895
  19. 421
  20. 372
  21. 956
  22. 491
  23. 936
  24. 249
  25. 424
  26. 354
  27. 780
  28. 338
  29. 323
  30. 771
  31. 647
  32. 381
  33. 460
  34. 613
  35. 1185
  36. 596
  37. 219
  38. 501
  39. 245
  40. 475

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