Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 880 · 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. 1.777 − 598 =
2. 2.969 − 497 =
3. 3.896 − 208 =
4. 4.522 − 198 =
5. 5.526 − 399 =
6. 6.882 − 699 =
7. 7.933 − 797 =
8. 8.238 − 199 =
9. 9.547 − 398 =
10. 10.840 − 299 =
11. 11.873 − 698 =
12. 12.819 − 398 =
13. 13.373 − 328 =
14. 14.653 − 549 =
15. 15.547 − 499 =
16. 16.861 − 799 =
17. 17.787 − 398 =
18. 18.622 − 328 =
19. 19.315 − 298 =
20. 20.419 − 199 =
21. 21.988 − 287 =
22. 22.598 − 509 =
23. 23.667 − 187 =
24. 24.960 − 699 =
25. 25.945 − 577 =
26. 26.730 − 539 =
27. 27.911 − 669 =
28. 28.643 − 497 =
29. 29.325 − 297 =
30. 30.630 − 237 =
31. 31.718 − 298 =
32. 32.740 − 478 =
33. 33.932 − 317 =
34. 34.453 − 299 =
35. 35.815 − 598 =
36. 36.479 − 289 =
37. 37.419 − 297 =
38. 38.389 − 168 =
39. 39.522 − 239 =
40. 40.601 − 397 =

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