Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 894 · 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. 1.871 − 397 =
2. 2.926 − 597 =
3. 3.447 − 299 =
4. 4.951 − 798 =
5. 5.981 − 198 =
6. 6.903 − 699 =
7. 7.954 − 599 =
8. 8.692 − 567 =
9. 9.965 − 569 =
10. 10.963 − 397 =
11. 11.909 − 698 =
12. 12.833 − 498 =
13. 13.615 − 198 =
14. 14.950 − 569 =
15. 15.642 − 259 =
16. 16.408 − 199 =
17. 17.782 − 389 =
18. 18.465 − 299 =
19. 19.219 − 179 =
20. 20.992 − 798 =
21. 21.586 − 187 =
22. 22.866 − 587 =
23. 23.877 − 138 =
24. 24.933 − 799 =
25. 25.760 − 628 =
26. 26.643 − 297 =
27. 27.520 − 119 =
28. 28.889 − 799 =
29. 29.666 − 299 =
30. 30.811 − 599 =
31. 31.593 − 487 =
32. 32.893 − 649 =
33. 33.886 − 567 =
34. 34.610 − 497 =
35. 35.641 − 498 =
36. 36.646 − 257 =
37. 37.767 − 557 =
38. 38.876 − 299 =
39. 39.435 − 137 =
40. 40.586 − 298 =

Free mental maths lessons, practice and worksheets at talentjr.in/mental-maths