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Add by Rounding Worksheet

Speed calculation lesson 2: Add by rounding · Set 21 · 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. 1.424 + 39 =
  2. 2.290 + 97 =
  3. 3.331 + 69 =
  4. 4.96 + 48 =
  5. 5.95 + 47 =
  6. 6.293 + 29 =
  7. 7.28 + 59 =
  8. 8.485 + 58 =
  9. 9.65 + 98 =
  10. 10.316 + 77 =
  11. 11.308 + 49 =
  12. 12.158 + 39 =
  13. 13.259 + 68 =
  14. 14.60 + 39 =
  15. 15.180 + 59 =
  16. 16.339 + 27 =
  17. 17.93 + 88 =
  18. 18.52 + 89 =
  19. 19.361 + 79 =
  20. 20.25 + 87 =
  21. 21.377 + 27 =
  22. 22.259 + 67 =
  23. 23.136 + 48 =
  24. 24.457 + 67 =
  25. 25.288 + 79 =
  26. 26.243 + 19 =
  27. 27.177 + 68 =
  28. 28.207 + 48 =
  29. 29.253 + 68 =
  30. 30.133 + 47 =
  31. 31.177 + 18 =
  32. 32.159 + 38 =
  33. 33.254 + 37 =
  34. 34.363 + 47 =
  35. 35.432 + 69 =
  36. 36.240 + 47 =
  37. 37.154 + 19 =
  38. 38.150 + 18 =
  39. 39.479 + 49 =
  40. 40.104 + 28 =

Answer key

  1. 463
  2. 387
  3. 400
  4. 144
  5. 142
  6. 322
  7. 87
  8. 543
  9. 163
  10. 393
  11. 357
  12. 197
  13. 327
  14. 99
  15. 239
  16. 366
  17. 181
  18. 141
  19. 440
  20. 112
  21. 404
  22. 326
  23. 184
  24. 524
  25. 367
  26. 262
  27. 245
  28. 255
  29. 321
  30. 180
  31. 195
  32. 197
  33. 291
  34. 410
  35. 501
  36. 287
  37. 173
  38. 168
  39. 528
  40. 132

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