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Add by Rounding Worksheet

Speed calculation lesson 2: Add by rounding · Set 241 · 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. 1.455 + 39 =
  2. 2.65 + 97 =
  3. 3.473 + 18 =
  4. 4.408 + 38 =
  5. 5.307 + 27 =
  6. 6.427 + 27 =
  7. 7.430 + 69 =
  8. 8.387 + 39 =
  9. 9.218 + 29 =
  10. 10.181 + 69 =
  11. 11.94 + 28 =
  12. 12.239 + 77 =
  13. 13.350 + 87 =
  14. 14.254 + 78 =
  15. 15.427 + 38 =
  16. 16.404 + 58 =
  17. 17.110 + 47 =
  18. 18.135 + 99 =
  19. 19.274 + 87 =
  20. 20.343 + 27 =
  21. 21.218 + 19 =
  22. 22.38 + 98 =
  23. 23.365 + 69 =
  24. 24.212 + 58 =
  25. 25.362 + 19 =
  26. 26.201 + 67 =
  27. 27.335 + 49 =
  28. 28.434 + 77 =
  29. 29.236 + 19 =
  30. 30.145 + 18 =
  31. 31.335 + 68 =
  32. 32.420 + 19 =
  33. 33.166 + 48 =
  34. 34.474 + 99 =
  35. 35.487 + 49 =
  36. 36.454 + 18 =
  37. 37.348 + 48 =
  38. 38.72 + 79 =
  39. 39.388 + 78 =
  40. 40.197 + 97 =

Answer key

  1. 494
  2. 162
  3. 491
  4. 446
  5. 334
  6. 454
  7. 499
  8. 426
  9. 247
  10. 250
  11. 122
  12. 316
  13. 437
  14. 332
  15. 465
  16. 462
  17. 157
  18. 234
  19. 361
  20. 370
  21. 237
  22. 136
  23. 434
  24. 270
  25. 381
  26. 268
  27. 384
  28. 511
  29. 255
  30. 163
  31. 403
  32. 439
  33. 214
  34. 573
  35. 536
  36. 472
  37. 396
  38. 151
  39. 466
  40. 294

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