Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 757 · 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. 1.896 − 497 =
2. 2.745 − 197 =
3. 3.695 − 398 =
4. 4.807 − 699 =
5. 5.634 − 597 =
6. 6.903 − 228 =
7. 7.565 − 527 =
8. 8.397 − 238 =
9. 9.940 − 698 =
10. 10.729 − 469 =
11. 11.803 − 597 =
12. 12.976 − 238 =
13. 13.864 − 199 =
14. 14.969 − 659 =
15. 15.701 − 679 =
16. 16.731 − 598 =
17. 17.932 − 799 =
18. 18.687 − 499 =
19. 19.572 − 497 =
20. 20.726 − 699 =
21. 21.603 − 548 =
22. 22.890 − 698 =
23. 23.760 − 497 =
24. 24.733 − 508 =
25. 25.441 − 197 =
26. 26.800 − 529 =
27. 27.535 − 198 =
28. 28.430 − 299 =
29. 29.389 − 297 =
30. 30.967 − 799 =
31. 31.935 − 558 =
32. 32.566 − 308 =
33. 33.265 − 207 =
34. 34.922 − 597 =
35. 35.366 − 197 =
36. 36.344 − 299 =
37. 37.986 − 398 =
38. 38.909 − 698 =
39. 39.866 − 597 =
40. 40.970 − 577 =

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