Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 73 · 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. 1.456 − 187 =
2. 2.705 − 499 =
3. 3.594 − 487 =
4. 4.592 − 397 =
5. 5.676 − 358 =
6. 6.866 − 799 =
7. 7.353 − 299 =
8. 8.238 − 198 =
9. 9.572 − 498 =
10. 10.446 − 198 =
11. 11.730 − 699 =
12. 12.884 − 178 =
13. 13.768 − 578 =
14. 14.691 − 379 =
15. 15.658 − 297 =
16. 16.815 − 597 =
17. 17.852 − 699 =
18. 18.542 − 298 =
19. 19.631 − 398 =
20. 20.778 − 198 =
21. 21.587 − 529 =
22. 22.938 − 197 =
23. 23.795 − 599 =
24. 24.677 − 387 =
25. 25.675 − 279 =
26. 26.794 − 619 =
27. 27.760 − 698 =
28. 28.896 − 669 =
29. 29.751 − 519 =
30. 30.959 − 797 =
31. 31.459 − 297 =
32. 32.408 − 299 =
33. 33.883 − 298 =
34. 34.918 − 239 =
35. 35.936 − 797 =
36. 36.879 − 189 =
37. 37.860 − 699 =
38. 38.830 − 519 =
39. 39.955 − 609 =
40. 40.629 − 597 =

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