Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 435 · 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. 1.748 − 527 =
2. 2.778 − 697 =
3. 3.931 − 699 =
4. 4.813 − 598 =
5. 5.549 − 397 =
6. 6.828 − 698 =
7. 7.348 − 258 =
8. 8.296 − 128 =
9. 9.869 − 798 =
10. 10.796 − 399 =
11. 11.784 − 399 =
12. 12.780 − 599 =
13. 13.750 − 697 =
14. 14.896 − 698 =
15. 15.888 − 799 =
16. 16.854 − 798 =
17. 17.887 − 368 =
18. 18.986 − 597 =
19. 19.706 − 197 =
20. 20.352 − 298 =
21. 21.180 − 157 =
22. 22.914 − 519 =
23. 23.468 − 129 =
24. 24.969 − 799 =
25. 25.738 − 597 =
26. 26.723 − 659 =
27. 27.736 − 599 =
28. 28.975 − 598 =
29. 29.698 − 228 =
30. 30.706 − 689 =
31. 31.610 − 567 =
32. 32.491 − 159 =
33. 33.942 − 399 =
34. 34.581 − 199 =
35. 35.808 − 197 =
36. 36.775 − 317 =
37. 37.417 − 397 =
38. 38.927 − 199 =
39. 39.944 − 697 =
40. 40.587 − 118 =

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