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Add by Rounding Worksheet

Speed calculation lesson 2: Add by rounding · Set 116 · 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. 1.306 + 99 =
  2. 2.125 + 19 =
  3. 3.312 + 67 =
  4. 4.430 + 99 =
  5. 5.64 + 89 =
  6. 6.241 + 69 =
  7. 7.193 + 17 =
  8. 8.402 + 98 =
  9. 9.464 + 69 =
  10. 10.55 + 68 =
  11. 11.454 + 88 =
  12. 12.302 + 18 =
  13. 13.473 + 18 =
  14. 14.113 + 49 =
  15. 15.159 + 18 =
  16. 16.358 + 38 =
  17. 17.252 + 38 =
  18. 18.197 + 18 =
  19. 19.225 + 97 =
  20. 20.375 + 79 =
  21. 21.264 + 29 =
  22. 22.446 + 19 =
  23. 23.43 + 38 =
  24. 24.483 + 87 =
  25. 25.288 + 77 =
  26. 26.389 + 48 =
  27. 27.133 + 27 =
  28. 28.430 + 58 =
  29. 29.350 + 19 =
  30. 30.41 + 77 =
  31. 31.36 + 57 =
  32. 32.69 + 88 =
  33. 33.199 + 27 =
  34. 34.338 + 98 =
  35. 35.142 + 47 =
  36. 36.333 + 59 =
  37. 37.100 + 97 =
  38. 38.202 + 48 =
  39. 39.51 + 39 =
  40. 40.339 + 47 =

Answer key

  1. 405
  2. 144
  3. 379
  4. 529
  5. 153
  6. 310
  7. 210
  8. 500
  9. 533
  10. 123
  11. 542
  12. 320
  13. 491
  14. 162
  15. 177
  16. 396
  17. 290
  18. 215
  19. 322
  20. 454
  21. 293
  22. 465
  23. 81
  24. 570
  25. 365
  26. 437
  27. 160
  28. 488
  29. 369
  30. 118
  31. 93
  32. 157
  33. 226
  34. 436
  35. 189
  36. 392
  37. 197
  38. 250
  39. 90
  40. 386

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