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Add by Rounding Worksheet

Speed calculation lesson 2: Add by rounding · Set 350 · 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. 1.141 + 29 =
  2. 2.313 + 18 =
  3. 3.108 + 68 =
  4. 4.259 + 47 =
  5. 5.115 + 78 =
  6. 6.415 + 38 =
  7. 7.187 + 89 =
  8. 8.113 + 18 =
  9. 9.126 + 98 =
  10. 10.253 + 59 =
  11. 11.426 + 39 =
  12. 12.65 + 38 =
  13. 13.159 + 77 =
  14. 14.52 + 89 =
  15. 15.431 + 28 =
  16. 16.281 + 39 =
  17. 17.76 + 27 =
  18. 18.331 + 78 =
  19. 19.314 + 87 =
  20. 20.282 + 19 =
  21. 21.218 + 68 =
  22. 22.257 + 57 =
  23. 23.428 + 48 =
  24. 24.251 + 29 =
  25. 25.122 + 89 =
  26. 26.312 + 48 =
  27. 27.348 + 38 =
  28. 28.466 + 79 =
  29. 29.402 + 17 =
  30. 30.76 + 59 =
  31. 31.362 + 97 =
  32. 32.122 + 47 =
  33. 33.249 + 78 =
  34. 34.432 + 18 =
  35. 35.342 + 27 =
  36. 36.391 + 49 =
  37. 37.266 + 29 =
  38. 38.263 + 57 =
  39. 39.78 + 79 =
  40. 40.353 + 89 =

Answer key

  1. 170
  2. 331
  3. 176
  4. 306
  5. 193
  6. 453
  7. 276
  8. 131
  9. 224
  10. 312
  11. 465
  12. 103
  13. 236
  14. 141
  15. 459
  16. 320
  17. 103
  18. 409
  19. 401
  20. 301
  21. 286
  22. 314
  23. 476
  24. 280
  25. 211
  26. 360
  27. 386
  28. 545
  29. 419
  30. 135
  31. 459
  32. 169
  33. 327
  34. 450
  35. 369
  36. 440
  37. 295
  38. 320
  39. 157
  40. 442

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