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Add by Rounding Worksheet

Speed calculation lesson 2: Add by rounding · Set 42 · 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. 1.454 + 69 =
  2. 2.133 + 18 =
  3. 3.333 + 58 =
  4. 4.155 + 17 =
  5. 5.462 + 79 =
  6. 6.141 + 17 =
  7. 7.224 + 78 =
  8. 8.388 + 87 =
  9. 9.247 + 28 =
  10. 10.285 + 59 =
  11. 11.315 + 17 =
  12. 12.112 + 38 =
  13. 13.76 + 97 =
  14. 14.361 + 37 =
  15. 15.351 + 39 =
  16. 16.471 + 98 =
  17. 17.235 + 18 =
  18. 18.286 + 17 =
  19. 19.32 + 18 =
  20. 20.427 + 77 =
  21. 21.373 + 87 =
  22. 22.262 + 39 =
  23. 23.151 + 19 =
  24. 24.50 + 99 =
  25. 25.447 + 99 =
  26. 26.136 + 69 =
  27. 27.472 + 48 =
  28. 28.393 + 18 =
  29. 29.497 + 48 =
  30. 30.203 + 17 =
  31. 31.476 + 47 =
  32. 32.297 + 69 =
  33. 33.157 + 17 =
  34. 34.443 + 68 =
  35. 35.73 + 77 =
  36. 36.43 + 87 =
  37. 37.182 + 49 =
  38. 38.68 + 87 =
  39. 39.106 + 29 =
  40. 40.212 + 47 =

Answer key

  1. 523
  2. 151
  3. 391
  4. 172
  5. 541
  6. 158
  7. 302
  8. 475
  9. 275
  10. 344
  11. 332
  12. 150
  13. 173
  14. 398
  15. 390
  16. 569
  17. 253
  18. 303
  19. 50
  20. 504
  21. 460
  22. 301
  23. 170
  24. 149
  25. 546
  26. 205
  27. 520
  28. 411
  29. 545
  30. 220
  31. 523
  32. 366
  33. 174
  34. 511
  35. 150
  36. 130
  37. 231
  38. 155
  39. 135
  40. 259

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