Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 393 · 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. 1.797 − 699 =
2. 2.320 − 208 =
3. 3.217 − 179 =
4. 4.822 − 799 =
5. 5.551 − 259 =
6. 6.257 − 218 =
7. 7.471 − 299 =
8. 8.684 − 239 =
9. 9.987 − 219 =
10. 10.774 − 498 =
11. 11.708 − 499 =
12. 12.848 − 799 =
13. 13.793 − 629 =
14. 14.782 − 427 =
15. 15.923 − 497 =
16. 16.699 − 497 =
17. 17.870 − 497 =
18. 18.712 − 697 =
19. 19.870 − 138 =
20. 20.712 − 698 =
21. 21.865 − 378 =
22. 22.676 − 229 =
23. 23.862 − 567 =
24. 24.737 − 298 =
25. 25.657 − 599 =
26. 26.631 − 127 =
27. 27.309 − 169 =
28. 28.753 − 139 =
29. 29.320 − 228 =
30. 30.585 − 118 =
31. 31.870 − 797 =
32. 32.792 − 638 =
33. 33.203 − 187 =
34. 34.528 − 398 =
35. 35.916 − 397 =
36. 36.969 − 799 =
37. 37.860 − 798 =
38. 38.873 − 699 =
39. 39.776 − 199 =
40. 40.846 − 597 =

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