Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 101 · 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. 1.513 − 497 =
2. 2.735 − 528 =
3. 3.478 − 398 =
4. 4.745 − 118 =
5. 5.612 − 198 =
6. 6.722 − 298 =
7. 7.992 − 499 =
8. 8.746 − 467 =
9. 9.716 − 618 =
10. 10.919 − 798 =
11. 11.986 − 598 =
12. 12.780 − 398 =
13. 13.230 − 159 =
14. 14.961 − 597 =
15. 15.916 − 287 =
16. 16.743 − 598 =
17. 17.868 − 239 =
18. 18.916 − 798 =
19. 19.950 − 599 =
20. 20.637 − 558 =
21. 21.986 − 597 =
22. 22.897 − 199 =
23. 23.934 − 538 =
24. 24.821 − 337 =
25. 25.677 − 398 =
26. 26.697 − 369 =
27. 27.965 − 299 =
28. 28.894 − 698 =
29. 29.830 − 797 =
30. 30.339 − 169 =
31. 31.946 − 599 =
32. 32.882 − 388 =
33. 33.623 − 579 =
34. 34.884 − 698 =
35. 35.662 − 597 =
36. 36.735 − 697 =
37. 37.891 − 697 =
38. 38.865 − 798 =
39. 39.182 − 169 =
40. 40.631 − 498 =

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