← 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 224 · 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. 1.564 − 426 =
  2. 2.937 − 212 =
  3. 3.576 + 225 =
  4. 4.259 + 296 =
  5. 5.248 + 479 =
  6. 6.884 − 188 =
  7. 7.748 − 445 =
  8. 8.666 + 548 =
  9. 9.968 − 163 =
  10. 10.461 + 294 =
  11. 11.622 − 303 =
  12. 12.714 + 479 =
  13. 13.770 + 509 =
  14. 14.741 − 141 =
  15. 15.199 + 244 =
  16. 16.340 + 584 =
  17. 17.647 + 629 =
  18. 18.627 − 433 =
  19. 19.565 − 226 =
  20. 20.597 + 292 =
  21. 21.532 + 431 =
  22. 22.616 − 164 =
  23. 23.746 + 318 =
  24. 24.323 + 536 =
  25. 25.958 − 213 =
  26. 26.893 − 175 =
  27. 27.665 − 347 =
  28. 28.522 + 192 =
  29. 29.518 − 121 =
  30. 30.428 + 495 =
  31. 31.188 + 291 =
  32. 32.474 + 681 =
  33. 33.971 − 151 =
  34. 34.136 + 157 =
  35. 35.278 + 425 =
  36. 36.395 + 128 =
  37. 37.346 + 518 =
  38. 38.544 − 246 =
  39. 39.541 − 131 =
  40. 40.910 − 348 =

Answer key

  1. 138
  2. 725
  3. 801
  4. 555
  5. 727
  6. 696
  7. 303
  8. 1214
  9. 805
  10. 755
  11. 319
  12. 1193
  13. 1279
  14. 600
  15. 443
  16. 924
  17. 1276
  18. 194
  19. 339
  20. 889
  21. 963
  22. 452
  23. 1064
  24. 859
  25. 745
  26. 718
  27. 318
  28. 714
  29. 397
  30. 923
  31. 479
  32. 1155
  33. 820
  34. 293
  35. 703
  36. 523
  37. 864
  38. 298
  39. 410
  40. 562

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