Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 430 · 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. 1.814 − 528 =
2. 2.974 − 619 =
3. 3.321 − 299 =
4. 4.988 − 388 =
5. 5.491 − 298 =
6. 6.747 − 698 =
7. 7.714 − 608 =
8. 8.751 − 698 =
9. 9.533 − 499 =
10. 10.768 − 677 =
11. 11.584 − 248 =
12. 12.641 − 597 =
13. 13.729 − 548 =
14. 14.633 − 619 =
15. 15.579 − 217 =
16. 16.728 − 699 =
17. 17.583 − 397 =
18. 18.220 − 187 =
19. 19.900 − 198 =
20. 20.831 − 138 =
21. 21.303 − 197 =
22. 22.849 − 179 =
23. 23.697 − 598 =
24. 24.807 − 598 =
25. 25.901 − 799 =
26. 26.990 − 459 =
27. 27.887 − 497 =
28. 28.656 − 389 =
29. 29.637 − 599 =
30. 30.679 − 399 =
31. 31.727 − 699 =
32. 32.816 − 798 =
33. 33.538 − 399 =
34. 34.257 − 149 =
35. 35.753 − 199 =
36. 36.794 − 318 =
37. 37.947 − 398 =
38. 38.819 − 698 =
39. 39.823 − 618 =
40. 40.311 − 198 =

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