Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 573 · 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. 1.752 − 398 =
2. 2.455 − 228 =
3. 3.715 − 598 =
4. 4.728 − 348 =
5. 5.702 − 119 =
6. 6.447 − 357 =
7. 7.672 − 137 =
8. 8.878 − 209 =
9. 9.998 − 547 =
10. 10.832 − 797 =
11. 11.576 − 398 =
12. 12.891 − 697 =
13. 13.912 − 797 =
14. 14.461 − 188 =
15. 15.939 − 638 =
16. 16.879 − 799 =
17. 17.226 − 198 =
18. 18.829 − 588 =
19. 19.908 − 378 =
20. 20.863 − 209 =
21. 21.602 − 418 =
22. 22.994 − 798 =
23. 23.937 − 797 =
24. 24.968 − 687 =
25. 25.991 − 669 =
26. 26.353 − 197 =
27. 27.418 − 338 =
28. 28.804 − 658 =
29. 29.373 − 199 =
30. 30.730 − 309 =
31. 31.623 − 219 =
32. 32.928 − 658 =
33. 33.418 − 199 =
34. 34.281 − 199 =
35. 35.923 − 498 =
36. 36.623 − 199 =
37. 37.952 − 299 =
38. 38.597 − 397 =
39. 39.946 − 349 =
40. 40.809 − 499 =

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