Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 582 · 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. 1.328 − 197 =
2. 2.671 − 647 =
3. 3.839 − 179 =
4. 4.879 − 439 =
5. 5.729 − 198 =
6. 6.897 − 597 =
7. 7.454 − 397 =
8. 8.935 − 598 =
9. 9.742 − 198 =
10. 10.379 − 298 =
11. 11.466 − 239 =
12. 12.302 − 198 =
13. 13.990 − 198 =
14. 14.888 − 397 =
15. 15.417 − 297 =
16. 16.648 − 137 =
17. 17.925 − 699 =
18. 18.406 − 297 =
19. 19.711 − 499 =
20. 20.740 − 298 =
21. 21.785 − 469 =
22. 22.982 − 798 =
23. 23.968 − 698 =
24. 24.583 − 497 =
25. 25.414 − 398 =
26. 26.836 − 198 =
27. 27.619 − 519 =
28. 28.892 − 408 =
29. 29.846 − 798 =
30. 30.410 − 199 =
31. 31.555 − 497 =
32. 32.867 − 318 =
33. 33.538 − 397 =
34. 34.922 − 698 =
35. 35.466 − 168 =
36. 36.891 − 697 =
37. 37.655 − 599 =
38. 38.715 − 298 =
39. 39.719 − 299 =
40. 40.867 − 799 =

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