← 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 473 · 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. 1.268 + 324 =
  2. 2.667 − 197 =
  3. 3.292 + 374 =
  4. 4.418 + 224 =
  5. 5.632 + 172 =
  6. 6.681 + 595 =
  7. 7.172 + 632 =
  8. 8.927 − 591 =
  9. 9.456 − 224 =
  10. 10.748 − 216 =
  11. 11.510 + 419 =
  12. 12.641 + 423 =
  13. 13.571 + 271 =
  14. 14.642 + 208 =
  15. 15.130 + 673 =
  16. 16.457 − 173 =
  17. 17.526 − 294 =
  18. 18.582 + 641 =
  19. 19.749 − 276 =
  20. 20.647 + 383 =
  21. 21.621 − 289 =
  22. 22.951 − 755 =
  23. 23.262 + 471 =
  24. 24.680 − 481 =
  25. 25.466 + 631 =
  26. 26.684 − 544 =
  27. 27.421 + 229 =
  28. 28.604 − 132 =
  29. 29.595 + 373 =
  30. 30.725 − 524 =
  31. 31.636 + 182 =
  32. 32.640 − 141 =
  33. 33.769 + 265 =
  34. 34.503 − 132 =
  35. 35.919 − 273 =
  36. 36.264 + 563 =
  37. 37.505 − 166 =
  38. 38.531 + 202 =
  39. 39.598 + 374 =
  40. 40.571 − 228 =

Answer key

  1. 592
  2. 470
  3. 666
  4. 642
  5. 804
  6. 1276
  7. 804
  8. 336
  9. 232
  10. 532
  11. 929
  12. 1064
  13. 842
  14. 850
  15. 803
  16. 284
  17. 232
  18. 1223
  19. 473
  20. 1030
  21. 332
  22. 196
  23. 733
  24. 199
  25. 1097
  26. 140
  27. 650
  28. 472
  29. 968
  30. 201
  31. 818
  32. 499
  33. 1034
  34. 371
  35. 646
  36. 827
  37. 339
  38. 733
  39. 972
  40. 343

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