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Add by Rounding Worksheet

Speed calculation lesson 2: Add by rounding · Set 434 · 40 questions
TalentJR

The fast method (Round up, then fix): Round the number ending in 7, 8 or 9 up to the next ten: 39 → 40. Add the round number. Take away the extra you added (here 1).

NameDateTime takenScore ___ / 40
  1. 1.350 + 99 =
  2. 2.359 + 88 =
  3. 3.175 + 37 =
  4. 4.314 + 19 =
  5. 5.362 + 98 =
  6. 6.62 + 48 =
  7. 7.104 + 28 =
  8. 8.322 + 38 =
  9. 9.209 + 79 =
  10. 10.380 + 68 =
  11. 11.321 + 68 =
  12. 12.373 + 87 =
  13. 13.426 + 98 =
  14. 14.89 + 88 =
  15. 15.394 + 58 =
  16. 16.268 + 58 =
  17. 17.236 + 68 =
  18. 18.94 + 89 =
  19. 19.90 + 37 =
  20. 20.244 + 49 =
  21. 21.60 + 59 =
  22. 22.106 + 19 =
  23. 23.499 + 27 =
  24. 24.370 + 49 =
  25. 25.184 + 47 =
  26. 26.82 + 98 =
  27. 27.498 + 37 =
  28. 28.109 + 87 =
  29. 29.85 + 38 =
  30. 30.127 + 79 =
  31. 31.178 + 79 =
  32. 32.299 + 47 =
  33. 33.388 + 18 =
  34. 34.344 + 77 =
  35. 35.31 + 28 =
  36. 36.319 + 49 =
  37. 37.224 + 18 =
  38. 38.394 + 47 =
  39. 39.27 + 88 =
  40. 40.389 + 39 =

Answer key

  1. 449
  2. 447
  3. 212
  4. 333
  5. 460
  6. 110
  7. 132
  8. 360
  9. 288
  10. 448
  11. 389
  12. 460
  13. 524
  14. 177
  15. 452
  16. 326
  17. 304
  18. 183
  19. 127
  20. 293
  21. 119
  22. 125
  23. 526
  24. 419
  25. 231
  26. 180
  27. 535
  28. 196
  29. 123
  30. 206
  31. 257
  32. 346
  33. 406
  34. 421
  35. 59
  36. 368
  37. 242
  38. 441
  39. 115
  40. 428

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