← 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 323 · 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. 1.219 + 441 =
  2. 2.591 + 449 =
  3. 3.789 − 222 =
  4. 4.422 + 164 =
  5. 5.353 + 419 =
  6. 6.210 + 688 =
  7. 7.507 − 306 =
  8. 8.301 + 143 =
  9. 9.878 − 531 =
  10. 10.280 + 211 =
  11. 11.439 − 301 =
  12. 12.576 + 357 =
  13. 13.207 + 273 =
  14. 14.558 + 563 =
  15. 15.455 + 284 =
  16. 16.458 + 247 =
  17. 17.440 − 247 =
  18. 18.364 + 684 =
  19. 19.567 − 274 =
  20. 20.820 − 652 =
  21. 21.225 + 686 =
  22. 22.519 + 622 =
  23. 23.777 − 628 =
  24. 24.556 − 145 =
  25. 25.985 − 142 =
  26. 26.783 + 267 =
  27. 27.733 + 517 =
  28. 28.457 − 319 =
  29. 29.599 − 136 =
  30. 30.466 + 452 =
  31. 31.609 + 253 =
  32. 32.902 − 674 =
  33. 33.710 − 116 =
  34. 34.182 + 205 =
  35. 35.543 + 203 =
  36. 36.818 − 497 =
  37. 37.957 − 381 =
  38. 38.362 + 195 =
  39. 39.961 − 636 =
  40. 40.213 + 531 =

Answer key

  1. 660
  2. 1040
  3. 567
  4. 586
  5. 772
  6. 898
  7. 201
  8. 444
  9. 347
  10. 491
  11. 138
  12. 933
  13. 480
  14. 1121
  15. 739
  16. 705
  17. 193
  18. 1048
  19. 293
  20. 168
  21. 911
  22. 1141
  23. 149
  24. 411
  25. 843
  26. 1050
  27. 1250
  28. 138
  29. 463
  30. 918
  31. 862
  32. 228
  33. 594
  34. 387
  35. 746
  36. 321
  37. 576
  38. 557
  39. 325
  40. 744

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