Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 841 · 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. 1.324 − 267 =
2. 2.611 − 288 =
3. 3.873 − 657 =
4. 4.783 − 299 =
5. 5.325 − 167 =
6. 6.801 − 118 =
7. 7.778 − 299 =
8. 8.796 − 179 =
9. 9.512 − 397 =
10. 10.594 − 338 =
11. 11.651 − 548 =
12. 12.683 − 619 =
13. 13.914 − 237 =
14. 14.558 − 408 =
15. 15.559 − 519 =
16. 16.604 − 367 =
17. 17.358 − 199 =
18. 18.877 − 597 =
19. 19.809 − 588 =
20. 20.642 − 398 =
21. 21.799 − 198 =
22. 22.647 − 299 =
23. 23.884 − 599 =
24. 24.624 − 197 =
25. 25.996 − 229 =
26. 26.612 − 199 =
27. 27.607 − 399 =
28. 28.805 − 129 =
29. 29.928 − 798 =
30. 30.990 − 798 =
31. 31.781 − 397 =
32. 32.793 − 599 =
33. 33.673 − 299 =
34. 34.931 − 798 =
35. 35.600 − 397 =
36. 36.265 − 227 =
37. 37.651 − 399 =
38. 38.508 − 388 =
39. 39.522 − 398 =
40. 40.854 − 798 =

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