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Add by Rounding Worksheet

Speed calculation lesson 2: Add by rounding · Set 354 · 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. 1.140 + 69 =
  2. 2.388 + 17 =
  3. 3.172 + 57 =
  4. 4.53 + 18 =
  5. 5.272 + 68 =
  6. 6.212 + 98 =
  7. 7.324 + 58 =
  8. 8.387 + 38 =
  9. 9.102 + 57 =
  10. 10.435 + 29 =
  11. 11.26 + 58 =
  12. 12.45 + 78 =
  13. 13.479 + 28 =
  14. 14.412 + 49 =
  15. 15.229 + 27 =
  16. 16.195 + 78 =
  17. 17.367 + 57 =
  18. 18.88 + 37 =
  19. 19.321 + 18 =
  20. 20.57 + 58 =
  21. 21.461 + 17 =
  22. 22.46 + 17 =
  23. 23.365 + 97 =
  24. 24.39 + 67 =
  25. 25.164 + 27 =
  26. 26.59 + 37 =
  27. 27.387 + 19 =
  28. 28.308 + 99 =
  29. 29.74 + 69 =
  30. 30.223 + 57 =
  31. 31.407 + 69 =
  32. 32.362 + 28 =
  33. 33.313 + 69 =
  34. 34.212 + 17 =
  35. 35.255 + 98 =
  36. 36.52 + 39 =
  37. 37.458 + 77 =
  38. 38.339 + 19 =
  39. 39.91 + 59 =
  40. 40.495 + 57 =

Answer key

  1. 209
  2. 405
  3. 229
  4. 71
  5. 340
  6. 310
  7. 382
  8. 425
  9. 159
  10. 464
  11. 84
  12. 123
  13. 507
  14. 461
  15. 256
  16. 273
  17. 424
  18. 125
  19. 339
  20. 115
  21. 478
  22. 63
  23. 462
  24. 106
  25. 191
  26. 96
  27. 406
  28. 407
  29. 143
  30. 280
  31. 476
  32. 390
  33. 382
  34. 229
  35. 353
  36. 91
  37. 535
  38. 358
  39. 150
  40. 552

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