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Add by Rounding Worksheet

Speed calculation lesson 2: Add by rounding · Set 425 · 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. 1.319 + 28 =
  2. 2.396 + 19 =
  3. 3.301 + 49 =
  4. 4.300 + 17 =
  5. 5.126 + 47 =
  6. 6.102 + 99 =
  7. 7.192 + 78 =
  8. 8.335 + 68 =
  9. 9.106 + 77 =
  10. 10.147 + 97 =
  11. 11.270 + 99 =
  12. 12.45 + 98 =
  13. 13.289 + 18 =
  14. 14.327 + 79 =
  15. 15.29 + 27 =
  16. 16.307 + 68 =
  17. 17.139 + 59 =
  18. 18.143 + 17 =
  19. 19.451 + 78 =
  20. 20.67 + 48 =
  21. 21.43 + 18 =
  22. 22.87 + 89 =
  23. 23.242 + 28 =
  24. 24.114 + 39 =
  25. 25.240 + 28 =
  26. 26.137 + 28 =
  27. 27.311 + 79 =
  28. 28.175 + 67 =
  29. 29.492 + 38 =
  30. 30.299 + 97 =
  31. 31.246 + 27 =
  32. 32.254 + 18 =
  33. 33.56 + 39 =
  34. 34.198 + 58 =
  35. 35.190 + 27 =
  36. 36.408 + 79 =
  37. 37.376 + 49 =
  38. 38.267 + 27 =
  39. 39.438 + 19 =
  40. 40.326 + 49 =

Answer key

  1. 347
  2. 415
  3. 350
  4. 317
  5. 173
  6. 201
  7. 270
  8. 403
  9. 183
  10. 244
  11. 369
  12. 143
  13. 307
  14. 406
  15. 56
  16. 375
  17. 198
  18. 160
  19. 529
  20. 115
  21. 61
  22. 176
  23. 270
  24. 153
  25. 268
  26. 165
  27. 390
  28. 242
  29. 530
  30. 396
  31. 273
  32. 272
  33. 95
  34. 256
  35. 217
  36. 487
  37. 425
  38. 294
  39. 457
  40. 375

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