Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 952 · 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. 1.630 − 498 =
2. 2.813 − 799 =
3. 3.955 − 597 =
4. 4.983 − 797 =
5. 5.944 − 599 =
6. 6.960 − 798 =
7. 7.887 − 248 =
8. 8.851 − 599 =
9. 9.899 − 688 =
10. 10.986 − 697 =
11. 11.781 − 198 =
12. 12.987 − 198 =
13. 13.633 − 398 =
14. 14.694 − 568 =
15. 15.801 − 299 =
16. 16.883 − 798 =
17. 17.790 − 147 =
18. 18.925 − 698 =
19. 19.978 − 798 =
20. 20.413 − 379 =
21. 21.701 − 288 =
22. 22.418 − 297 =
23. 23.719 − 368 =
24. 24.863 − 198 =
25. 25.526 − 188 =
26. 26.925 − 797 =
27. 27.753 − 369 =
28. 28.610 − 199 =
29. 29.749 − 417 =
30. 30.964 − 598 =
31. 31.497 − 167 =
32. 32.691 − 418 =
33. 33.934 − 499 =
34. 34.963 − 428 =
35. 35.719 − 668 =
36. 36.835 − 509 =
37. 37.556 − 499 =
38. 38.266 − 159 =
39. 39.420 − 297 =
40. 40.510 − 437 =

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