← 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 968 · 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. 1.515 + 503 =
  2. 2.130 + 221 =
  3. 3.698 − 375 =
  4. 4.767 + 538 =
  5. 5.657 + 464 =
  6. 6.410 + 542 =
  7. 7.695 + 559 =
  8. 8.830 − 511 =
  9. 9.448 + 151 =
  10. 10.624 + 288 =
  11. 11.347 + 511 =
  12. 12.458 + 216 =
  13. 13.534 + 181 =
  14. 14.879 − 224 =
  15. 15.765 − 567 =
  16. 16.469 − 339 =
  17. 17.791 − 289 =
  18. 18.220 + 434 =
  19. 19.748 + 521 =
  20. 20.371 + 181 =
  21. 21.274 + 363 =
  22. 22.719 − 206 =
  23. 23.541 − 267 =
  24. 24.746 + 261 =
  25. 25.364 + 288 =
  26. 26.464 − 342 =
  27. 27.736 + 634 =
  28. 28.363 + 295 =
  29. 29.451 − 231 =
  30. 30.202 + 403 =
  31. 31.415 + 586 =
  32. 32.554 + 251 =
  33. 33.436 − 309 =
  34. 34.778 + 113 =
  35. 35.813 − 194 =
  36. 36.400 + 257 =
  37. 37.629 + 181 =
  38. 38.583 + 464 =
  39. 39.699 + 541 =
  40. 40.771 + 424 =

Answer key

  1. 1018
  2. 351
  3. 323
  4. 1305
  5. 1121
  6. 952
  7. 1254
  8. 319
  9. 599
  10. 912
  11. 858
  12. 674
  13. 715
  14. 655
  15. 198
  16. 130
  17. 502
  18. 654
  19. 1269
  20. 552
  21. 637
  22. 513
  23. 274
  24. 1007
  25. 652
  26. 122
  27. 1370
  28. 658
  29. 220
  30. 605
  31. 1001
  32. 805
  33. 127
  34. 891
  35. 619
  36. 657
  37. 810
  38. 1047
  39. 1240
  40. 1195

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