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Add by Rounding Worksheet

Speed calculation lesson 2: Add by rounding · Set 555 · 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. 1.391 + 37 =
  2. 2.459 + 57 =
  3. 3.149 + 89 =
  4. 4.257 + 78 =
  5. 5.172 + 39 =
  6. 6.159 + 99 =
  7. 7.183 + 68 =
  8. 8.303 + 47 =
  9. 9.394 + 19 =
  10. 10.249 + 67 =
  11. 11.374 + 59 =
  12. 12.447 + 68 =
  13. 13.259 + 18 =
  14. 14.73 + 28 =
  15. 15.283 + 37 =
  16. 16.65 + 98 =
  17. 17.478 + 68 =
  18. 18.30 + 37 =
  19. 19.71 + 18 =
  20. 20.443 + 28 =
  21. 21.406 + 77 =
  22. 22.249 + 48 =
  23. 23.190 + 39 =
  24. 24.372 + 19 =
  25. 25.377 + 77 =
  26. 26.499 + 18 =
  27. 27.164 + 37 =
  28. 28.492 + 97 =
  29. 29.161 + 59 =
  30. 30.103 + 79 =
  31. 31.253 + 97 =
  32. 32.461 + 38 =
  33. 33.394 + 37 =
  34. 34.353 + 77 =
  35. 35.228 + 99 =
  36. 36.53 + 17 =
  37. 37.53 + 47 =
  38. 38.107 + 58 =
  39. 39.106 + 29 =
  40. 40.299 + 59 =

Answer key

  1. 428
  2. 516
  3. 238
  4. 335
  5. 211
  6. 258
  7. 251
  8. 350
  9. 413
  10. 316
  11. 433
  12. 515
  13. 277
  14. 101
  15. 320
  16. 163
  17. 546
  18. 67
  19. 89
  20. 471
  21. 483
  22. 297
  23. 229
  24. 391
  25. 454
  26. 517
  27. 201
  28. 589
  29. 220
  30. 182
  31. 350
  32. 499
  33. 431
  34. 430
  35. 327
  36. 70
  37. 100
  38. 165
  39. 135
  40. 358

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