← Add by rounding lesson New set →

Add by Rounding Worksheet

Speed calculation lesson 2: Add by rounding · Set 161 · 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. 1.370 + 38 =
  2. 2.408 + 59 =
  3. 3.75 + 28 =
  4. 4.231 + 79 =
  5. 5.348 + 58 =
  6. 6.138 + 19 =
  7. 7.387 + 28 =
  8. 8.90 + 57 =
  9. 9.372 + 88 =
  10. 10.491 + 48 =
  11. 11.348 + 49 =
  12. 12.481 + 28 =
  13. 13.469 + 69 =
  14. 14.485 + 59 =
  15. 15.440 + 49 =
  16. 16.339 + 88 =
  17. 17.115 + 39 =
  18. 18.335 + 39 =
  19. 19.171 + 57 =
  20. 20.208 + 69 =
  21. 21.387 + 29 =
  22. 22.493 + 88 =
  23. 23.289 + 97 =
  24. 24.197 + 18 =
  25. 25.37 + 79 =
  26. 26.123 + 17 =
  27. 27.253 + 27 =
  28. 28.327 + 97 =
  29. 29.217 + 57 =
  30. 30.167 + 78 =
  31. 31.486 + 17 =
  32. 32.330 + 57 =
  33. 33.419 + 98 =
  34. 34.196 + 68 =
  35. 35.361 + 29 =
  36. 36.461 + 29 =
  37. 37.100 + 89 =
  38. 38.312 + 67 =
  39. 39.190 + 19 =
  40. 40.283 + 47 =

Answer key

  1. 408
  2. 467
  3. 103
  4. 310
  5. 406
  6. 157
  7. 415
  8. 147
  9. 460
  10. 539
  11. 397
  12. 509
  13. 538
  14. 544
  15. 489
  16. 427
  17. 154
  18. 374
  19. 228
  20. 277
  21. 416
  22. 581
  23. 386
  24. 215
  25. 116
  26. 140
  27. 280
  28. 424
  29. 274
  30. 245
  31. 503
  32. 387
  33. 517
  34. 264
  35. 390
  36. 490
  37. 189
  38. 379
  39. 209
  40. 330

Free speed calculation lessons, practice and worksheets at talentjr.in/speed-maths