Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 778 · 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. 1.917 − 227 =
2. 2.865 − 498 =
3. 3.953 − 497 =
4. 4.715 − 299 =
5. 5.752 − 297 =
6. 6.834 − 798 =
7. 7.727 − 498 =
8. 8.957 − 658 =
9. 9.616 − 398 =
10. 10.733 − 597 =
11. 11.978 − 427 =
12. 12.901 − 637 =
13. 13.755 − 309 =
14. 14.812 − 299 =
15. 15.791 − 238 =
16. 16.263 − 189 =
17. 17.761 − 518 =
18. 18.723 − 468 =
19. 19.602 − 499 =
20. 20.779 − 699 =
21. 21.279 − 207 =
22. 22.790 − 598 =
23. 23.260 − 148 =
24. 24.556 − 297 =
25. 25.824 − 598 =
26. 26.899 − 399 =
27. 27.870 − 797 =
28. 28.744 − 499 =
29. 29.990 − 597 =
30. 30.478 − 198 =
31. 31.962 − 687 =
32. 32.983 − 597 =
33. 33.924 − 397 =
34. 34.404 − 297 =
35. 35.370 − 297 =
36. 36.840 − 598 =
37. 37.817 − 467 =
38. 38.968 − 599 =
39. 39.357 − 208 =
40. 40.834 − 699 =

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