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Add by Rounding Worksheet

Speed calculation lesson 2: Add by rounding · Set 831 · 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. 1.450 + 59 =
  2. 2.127 + 37 =
  3. 3.200 + 37 =
  4. 4.345 + 97 =
  5. 5.236 + 68 =
  6. 6.149 + 37 =
  7. 7.55 + 49 =
  8. 8.151 + 38 =
  9. 9.444 + 57 =
  10. 10.283 + 37 =
  11. 11.44 + 47 =
  12. 12.89 + 28 =
  13. 13.430 + 47 =
  14. 14.437 + 17 =
  15. 15.195 + 78 =
  16. 16.348 + 48 =
  17. 17.424 + 79 =
  18. 18.274 + 78 =
  19. 19.177 + 17 =
  20. 20.101 + 38 =
  21. 21.321 + 27 =
  22. 22.398 + 87 =
  23. 23.484 + 28 =
  24. 24.317 + 78 =
  25. 25.111 + 39 =
  26. 26.106 + 17 =
  27. 27.237 + 37 =
  28. 28.28 + 87 =
  29. 29.48 + 17 =
  30. 30.495 + 57 =
  31. 31.125 + 29 =
  32. 32.369 + 89 =
  33. 33.493 + 57 =
  34. 34.140 + 99 =
  35. 35.140 + 27 =
  36. 36.129 + 37 =
  37. 37.176 + 88 =
  38. 38.144 + 68 =
  39. 39.30 + 17 =
  40. 40.378 + 49 =

Answer key

  1. 509
  2. 164
  3. 237
  4. 442
  5. 304
  6. 186
  7. 104
  8. 189
  9. 501
  10. 320
  11. 91
  12. 117
  13. 477
  14. 454
  15. 273
  16. 396
  17. 503
  18. 352
  19. 194
  20. 139
  21. 348
  22. 485
  23. 512
  24. 395
  25. 150
  26. 123
  27. 274
  28. 115
  29. 65
  30. 552
  31. 154
  32. 458
  33. 550
  34. 239
  35. 167
  36. 166
  37. 264
  38. 212
  39. 47
  40. 427

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