Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 592 · 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. 1.649 − 248 =
2. 2.830 − 499 =
3. 3.483 − 299 =
4. 4.843 − 698 =
5. 5.518 − 199 =
6. 6.790 − 697 =
7. 7.614 − 497 =
8. 8.712 − 649 =
9. 9.358 − 298 =
10. 10.630 − 318 =
11. 11.830 − 799 =
12. 12.857 − 199 =
13. 13.383 − 368 =
14. 14.650 − 449 =
15. 15.928 − 798 =
16. 16.774 − 389 =
17. 17.874 − 799 =
18. 18.764 − 498 =
19. 19.941 − 669 =
20. 20.690 − 548 =
21. 21.947 − 797 =
22. 22.490 − 397 =
23. 23.874 − 398 =
24. 24.997 − 399 =
25. 25.937 − 297 =
26. 26.640 − 199 =
27. 27.800 − 167 =
28. 28.718 − 658 =
29. 29.851 − 699 =
30. 30.994 − 598 =
31. 31.759 − 317 =
32. 32.958 − 197 =
33. 33.823 − 399 =
34. 34.814 − 799 =
35. 35.927 − 298 =
36. 36.801 − 398 =
37. 37.862 − 799 =
38. 38.922 − 197 =
39. 39.769 − 599 =
40. 40.547 − 418 =

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