Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 410 · 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. 1.701 − 499 =
2. 2.754 − 699 =
3. 3.216 − 199 =
4. 4.924 − 397 =
5. 5.653 − 399 =
6. 6.731 − 298 =
7. 7.866 − 369 =
8. 8.606 − 228 =
9. 9.689 − 597 =
10. 10.985 − 699 =
11. 11.701 − 517 =
12. 12.767 − 549 =
13. 13.759 − 698 =
14. 14.538 − 317 =
15. 15.244 − 147 =
16. 16.820 − 587 =
17. 17.919 − 799 =
18. 18.498 − 239 =
19. 19.844 − 649 =
20. 20.542 − 507 =
21. 21.946 − 797 =
22. 22.791 − 309 =
23. 23.975 − 479 =
24. 24.787 − 699 =
25. 25.820 − 798 =
26. 26.485 − 138 =
27. 27.829 − 617 =
28. 28.256 − 197 =
29. 29.743 − 299 =
30. 30.569 − 417 =
31. 31.845 − 798 =
32. 32.857 − 697 =
33. 33.562 − 297 =
34. 34.981 − 197 =
35. 35.757 − 119 =
36. 36.825 − 197 =
37. 37.726 − 397 =
38. 38.970 − 599 =
39. 39.441 − 198 =
40. 40.952 − 288 =

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