Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 515 · 40 questions

How to do it in your head (Round up, add back): Round the number you take away up to the next ten or hundred: 297 → 300 (3 too many). Take away the round number. Add back the extra, because you took away too much.

1. 1.595 − 179 =
2. 2.952 − 799 =
3. 3.852 − 339 =
4. 4.827 − 537 =
5. 5.889 − 797 =
6. 6.701 − 368 =
7. 7.289 − 138 =
8. 8.290 − 197 =
9. 9.905 − 199 =
10. 10.269 − 118 =
11. 11.202 − 189 =
12. 12.796 − 698 =
13. 13.480 − 398 =
14. 14.383 − 299 =
15. 15.572 − 247 =
16. 16.798 − 328 =
17. 17.735 − 697 =
18. 18.912 − 627 =
19. 19.511 − 449 =
20. 20.973 − 798 =
21. 21.767 − 199 =
22. 22.891 − 447 =
23. 23.799 − 397 =
24. 24.914 − 699 =
25. 25.903 − 677 =
26. 26.902 − 628 =
27. 27.675 − 599 =
28. 28.891 − 598 =
29. 29.947 − 607 =
30. 30.694 − 587 =
31. 31.803 − 497 =
32. 32.671 − 199 =
33. 33.932 − 197 =
34. 34.858 − 797 =
35. 35.829 − 498 =
36. 36.789 − 287 =
37. 37.780 − 699 =
38. 38.532 − 409 =
39. 39.783 − 438 =
40. 40.507 − 298 =

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