Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 282 · 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. 1.826 − 697 =
2. 2.143 − 118 =
3. 3.844 − 687 =
4. 4.544 − 499 =
5. 5.845 − 598 =
6. 6.922 − 598 =
7. 7.644 − 467 =
8. 8.485 − 297 =
9. 9.693 − 517 =
10. 10.531 − 248 =
11. 11.637 − 587 =
12. 12.881 − 497 =
13. 13.770 − 297 =
14. 14.652 − 477 =
15. 15.820 − 699 =
16. 16.410 − 347 =
17. 17.871 − 699 =
18. 18.958 − 597 =
19. 19.501 − 299 =
20. 20.361 − 217 =
21. 21.987 − 797 =
22. 22.702 − 577 =
23. 23.724 − 318 =
24. 24.742 − 599 =
25. 25.598 − 297 =
26. 26.899 − 499 =
27. 27.903 − 397 =
28. 28.957 − 577 =
29. 29.972 − 499 =
30. 30.586 − 499 =
31. 31.372 − 138 =
32. 32.859 − 299 =
33. 33.940 − 799 =
34. 34.691 − 668 =
35. 35.878 − 397 =
36. 36.739 − 199 =
37. 37.492 − 138 =
38. 38.937 − 699 =
39. 39.953 − 618 =
40. 40.830 − 799 =

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