← 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 909 · 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. 1.647 − 386 =
  2. 2.173 + 394 =
  3. 3.760 + 203 =
  4. 4.214 + 514 =
  5. 5.476 − 327 =
  6. 6.583 + 252 =
  7. 7.885 − 599 =
  8. 8.487 − 325 =
  9. 9.959 − 292 =
  10. 10.251 + 171 =
  11. 11.799 − 422 =
  12. 12.726 + 119 =
  13. 13.605 + 205 =
  14. 14.218 + 654 =
  15. 15.229 + 241 =
  16. 16.677 + 421 =
  17. 17.305 + 224 =
  18. 18.697 − 273 =
  19. 19.686 + 558 =
  20. 20.483 − 288 =
  21. 21.398 + 362 =
  22. 22.505 + 231 =
  23. 23.284 + 194 =
  24. 24.514 − 238 =
  25. 25.621 + 181 =
  26. 26.846 − 483 =
  27. 27.418 − 301 =
  28. 28.923 − 471 =
  29. 29.660 − 145 =
  30. 30.448 + 655 =
  31. 31.312 + 453 =
  32. 32.491 − 272 =
  33. 33.984 − 647 =
  34. 34.340 + 136 =
  35. 35.386 + 642 =
  36. 36.880 − 378 =
  37. 37.571 − 439 =
  38. 38.570 − 313 =
  39. 39.574 + 134 =
  40. 40.749 − 194 =

Answer key

  1. 261
  2. 567
  3. 963
  4. 728
  5. 149
  6. 835
  7. 286
  8. 162
  9. 667
  10. 422
  11. 377
  12. 845
  13. 810
  14. 872
  15. 470
  16. 1098
  17. 529
  18. 424
  19. 1244
  20. 195
  21. 760
  22. 736
  23. 478
  24. 276
  25. 802
  26. 363
  27. 117
  28. 452
  29. 515
  30. 1103
  31. 765
  32. 219
  33. 337
  34. 476
  35. 1028
  36. 502
  37. 132
  38. 257
  39. 708
  40. 555

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