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3-Digit Mental Addition and Subtraction Worksheet

Mental maths lesson 20: Add and subtract 3-digit numbers left to right · Set 589 · 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. 1.964 − 419 =
  2. 2.960 − 321 =
  3. 3.700 + 604 =
  4. 4.752 + 191 =
  5. 5.257 + 411 =
  6. 6.845 − 591 =
  7. 7.476 − 244 =
  8. 8.445 − 261 =
  9. 9.159 + 616 =
  10. 10.437 − 114 =
  11. 11.173 + 622 =
  12. 12.341 + 177 =
  13. 13.535 − 283 =
  14. 14.403 + 501 =
  15. 15.750 − 336 =
  16. 16.199 + 249 =
  17. 17.608 − 456 =
  18. 18.518 − 371 =
  19. 19.590 − 172 =
  20. 20.555 + 245 =
  21. 21.372 + 122 =
  22. 22.625 + 588 =
  23. 23.613 + 448 =
  24. 24.257 + 229 =
  25. 25.155 + 479 =
  26. 26.596 + 531 =
  27. 27.304 + 299 =
  28. 28.159 + 195 =
  29. 29.977 − 592 =
  30. 30.151 + 296 =
  31. 31.479 + 496 =
  32. 32.417 − 291 =
  33. 33.430 − 121 =
  34. 34.904 − 748 =
  35. 35.784 − 481 =
  36. 36.472 − 136 =
  37. 37.615 − 179 =
  38. 38.257 + 353 =
  39. 39.801 − 565 =
  40. 40.126 + 673 =

Answer key

  1. 545
  2. 639
  3. 1304
  4. 943
  5. 668
  6. 254
  7. 232
  8. 184
  9. 775
  10. 323
  11. 795
  12. 518
  13. 252
  14. 904
  15. 414
  16. 448
  17. 152
  18. 147
  19. 418
  20. 800
  21. 494
  22. 1213
  23. 1061
  24. 486
  25. 634
  26. 1127
  27. 603
  28. 354
  29. 385
  30. 447
  31. 975
  32. 126
  33. 309
  34. 156
  35. 303
  36. 336
  37. 436
  38. 610
  39. 236
  40. 799

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