Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 30 · 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. 1.779 − 177 =
2. 2.313 − 188 =
3. 3.571 − 297 =
4. 4.752 − 639 =
5. 5.864 − 697 =
6. 6.838 − 597 =
7. 7.895 − 298 =
8. 8.500 − 117 =
9. 9.868 − 499 =
10. 10.718 − 397 =
11. 11.588 − 549 =
12. 12.980 − 547 =
13. 13.865 − 799 =
14. 14.694 − 648 =
15. 15.861 − 798 =
16. 16.922 − 799 =
17. 17.694 − 397 =
18. 18.969 − 499 =
19. 19.427 − 129 =
20. 20.813 − 797 =
21. 21.760 − 697 =
22. 22.326 − 198 =
23. 23.497 − 438 =
24. 24.963 − 799 =
25. 25.664 − 498 =
26. 26.867 − 698 =
27. 27.620 − 498 =
28. 28.568 − 498 =
29. 29.815 − 799 =
30. 30.816 − 198 =
31. 31.794 − 118 =
32. 32.568 − 397 =
33. 33.943 − 297 =
34. 34.699 − 468 =
35. 35.785 − 299 =
36. 36.838 − 668 =
37. 37.686 − 599 =
38. 38.393 − 187 =
39. 39.661 − 597 =
40. 40.683 − 597 =

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