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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 966 · 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. 1.980 − 252 =
  2. 2.627 + 336 =
  3. 3.409 + 263 =
  4. 4.164 + 681 =
  5. 5.804 − 211 =
  6. 6.811 − 246 =
  7. 7.188 + 223 =
  8. 8.782 − 412 =
  9. 9.716 − 571 =
  10. 10.732 − 251 =
  11. 11.504 − 301 =
  12. 12.516 − 307 =
  13. 13.697 + 291 =
  14. 14.219 + 323 =
  15. 15.486 − 161 =
  16. 16.477 + 451 =
  17. 17.692 − 583 =
  18. 18.541 + 359 =
  19. 19.276 + 593 =
  20. 20.428 + 557 =
  21. 21.401 + 648 =
  22. 22.855 − 284 =
  23. 23.436 − 182 =
  24. 24.471 + 461 =
  25. 25.422 + 184 =
  26. 26.711 + 381 =
  27. 27.334 + 342 =
  28. 28.358 + 645 =
  29. 29.606 − 413 =
  30. 30.624 + 258 =
  31. 31.170 + 117 =
  32. 32.238 + 397 =
  33. 33.726 − 354 =
  34. 34.276 + 521 =
  35. 35.129 + 212 =
  36. 36.855 − 229 =
  37. 37.963 − 456 =
  38. 38.138 + 167 =
  39. 39.533 − 175 =
  40. 40.327 + 226 =

Answer key

  1. 728
  2. 963
  3. 672
  4. 845
  5. 593
  6. 565
  7. 411
  8. 370
  9. 145
  10. 481
  11. 203
  12. 209
  13. 988
  14. 542
  15. 325
  16. 928
  17. 109
  18. 900
  19. 869
  20. 985
  21. 1049
  22. 571
  23. 254
  24. 932
  25. 606
  26. 1092
  27. 676
  28. 1003
  29. 193
  30. 882
  31. 287
  32. 635
  33. 372
  34. 797
  35. 341
  36. 626
  37. 507
  38. 305
  39. 358
  40. 553

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