← 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 140 · 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. 1.686 − 464 =
  2. 2.205 + 211 =
  3. 3.923 − 141 =
  4. 4.496 + 214 =
  5. 5.580 − 151 =
  6. 6.438 − 157 =
  7. 7.696 − 166 =
  8. 8.624 + 201 =
  9. 9.657 + 667 =
  10. 10.650 − 186 =
  11. 11.913 − 724 =
  12. 12.643 + 281 =
  13. 13.431 + 605 =
  14. 14.310 + 407 =
  15. 15.131 + 356 =
  16. 16.639 + 181 =
  17. 17.871 − 401 =
  18. 18.333 + 401 =
  19. 19.741 + 154 =
  20. 20.450 − 334 =
  21. 21.130 + 654 =
  22. 22.780 + 411 =
  23. 23.453 − 172 =
  24. 24.632 + 129 =
  25. 25.160 + 621 =
  26. 26.699 − 444 =
  27. 27.341 + 588 =
  28. 28.264 + 435 =
  29. 29.461 + 427 =
  30. 30.705 + 625 =
  31. 31.353 + 121 =
  32. 32.635 − 153 =
  33. 33.554 − 223 =
  34. 34.597 + 252 =
  35. 35.628 + 483 =
  36. 36.592 − 157 =
  37. 37.577 + 677 =
  38. 38.204 + 667 =
  39. 39.195 + 153 =
  40. 40.590 + 297 =

Answer key

  1. 222
  2. 416
  3. 782
  4. 710
  5. 429
  6. 281
  7. 530
  8. 825
  9. 1324
  10. 464
  11. 189
  12. 924
  13. 1036
  14. 717
  15. 487
  16. 820
  17. 470
  18. 734
  19. 895
  20. 116
  21. 784
  22. 1191
  23. 281
  24. 761
  25. 781
  26. 255
  27. 929
  28. 699
  29. 888
  30. 1330
  31. 474
  32. 482
  33. 331
  34. 849
  35. 1111
  36. 435
  37. 1254
  38. 871
  39. 348
  40. 887

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