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Add by Rounding Worksheet

Speed calculation lesson 2: Add by rounding · Set 639 · 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. 1.179 + 48 =
  2. 2.261 + 78 =
  3. 3.132 + 18 =
  4. 4.219 + 37 =
  5. 5.58 + 39 =
  6. 6.305 + 68 =
  7. 7.181 + 17 =
  8. 8.354 + 87 =
  9. 9.348 + 19 =
  10. 10.210 + 29 =
  11. 11.48 + 18 =
  12. 12.90 + 18 =
  13. 13.289 + 47 =
  14. 14.274 + 88 =
  15. 15.272 + 99 =
  16. 16.327 + 99 =
  17. 17.50 + 39 =
  18. 18.415 + 28 =
  19. 19.107 + 29 =
  20. 20.471 + 79 =
  21. 21.360 + 48 =
  22. 22.333 + 37 =
  23. 23.50 + 78 =
  24. 24.246 + 68 =
  25. 25.295 + 37 =
  26. 26.160 + 17 =
  27. 27.64 + 58 =
  28. 28.192 + 38 =
  29. 29.285 + 99 =
  30. 30.93 + 29 =
  31. 31.496 + 47 =
  32. 32.430 + 98 =
  33. 33.183 + 57 =
  34. 34.49 + 98 =
  35. 35.186 + 79 =
  36. 36.97 + 48 =
  37. 37.35 + 18 =
  38. 38.450 + 38 =
  39. 39.367 + 37 =
  40. 40.297 + 29 =

Answer key

  1. 227
  2. 339
  3. 150
  4. 256
  5. 97
  6. 373
  7. 198
  8. 441
  9. 367
  10. 239
  11. 66
  12. 108
  13. 336
  14. 362
  15. 371
  16. 426
  17. 89
  18. 443
  19. 136
  20. 550
  21. 408
  22. 370
  23. 128
  24. 314
  25. 332
  26. 177
  27. 122
  28. 230
  29. 384
  30. 122
  31. 543
  32. 528
  33. 240
  34. 147
  35. 265
  36. 145
  37. 53
  38. 488
  39. 404
  40. 326

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