Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 152 · 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. 1.985 − 229 =
2. 2.968 − 797 =
3. 3.804 − 198 =
4. 4.685 − 298 =
5. 5.523 − 449 =
6. 6.867 − 539 =
7. 7.822 − 549 =
8. 8.533 − 198 =
9. 9.450 − 209 =
10. 10.343 − 287 =
11. 11.721 − 458 =
12. 12.703 − 609 =
13. 13.990 − 697 =
14. 14.969 − 699 =
15. 15.261 − 149 =
16. 16.720 − 628 =
17. 17.987 − 498 =
18. 18.365 − 198 =
19. 19.972 − 697 =
20. 20.621 − 148 =
21. 21.948 − 799 =
22. 22.825 − 799 =
23. 23.664 − 417 =
24. 24.511 − 198 =
25. 25.949 − 647 =
26. 26.746 − 597 =
27. 27.617 − 469 =
28. 28.296 − 198 =
29. 29.887 − 518 =
30. 30.492 − 167 =
31. 31.985 − 597 =
32. 32.833 − 199 =
33. 33.941 − 657 =
34. 34.753 − 697 =
35. 35.519 − 299 =
36. 36.725 − 169 =
37. 37.907 − 479 =
38. 38.655 − 567 =
39. 39.839 − 139 =
40. 40.976 − 699 =

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