← 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 107 · 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. 1.920 − 175 =
  2. 2.162 + 216 =
  3. 3.360 + 613 =
  4. 4.879 − 126 =
  5. 5.412 − 254 =
  6. 6.972 − 294 =
  7. 7.409 + 288 =
  8. 8.719 − 146 =
  9. 9.639 + 251 =
  10. 10.477 − 188 =
  11. 11.521 − 141 =
  12. 12.399 + 261 =
  13. 13.833 − 298 =
  14. 14.515 + 544 =
  15. 15.426 − 122 =
  16. 16.510 + 342 =
  17. 17.848 − 591 =
  18. 18.504 + 123 =
  19. 19.899 − 548 =
  20. 20.774 − 566 =
  21. 21.377 + 115 =
  22. 22.442 − 278 =
  23. 23.435 + 263 =
  24. 24.588 − 427 =
  25. 25.711 + 302 =
  26. 26.467 − 207 =
  27. 27.339 + 429 =
  28. 28.351 + 165 =
  29. 29.919 − 159 =
  30. 30.763 − 597 =
  31. 31.830 − 261 =
  32. 32.557 + 655 =
  33. 33.409 + 281 =
  34. 34.250 + 359 =
  35. 35.307 + 411 =
  36. 36.520 − 312 =
  37. 37.412 + 237 =
  38. 38.566 + 534 =
  39. 39.208 + 538 =
  40. 40.208 + 223 =

Answer key

  1. 745
  2. 378
  3. 973
  4. 753
  5. 158
  6. 678
  7. 697
  8. 573
  9. 890
  10. 289
  11. 380
  12. 660
  13. 535
  14. 1059
  15. 304
  16. 852
  17. 257
  18. 627
  19. 351
  20. 208
  21. 492
  22. 164
  23. 698
  24. 161
  25. 1013
  26. 260
  27. 768
  28. 516
  29. 760
  30. 166
  31. 569
  32. 1212
  33. 690
  34. 609
  35. 718
  36. 208
  37. 649
  38. 1100
  39. 746
  40. 431

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