Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 895 · 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. 1.626 − 609 =
2. 2.532 − 397 =
3. 3.837 − 798 =
4. 4.734 − 329 =
5. 5.733 − 497 =
6. 6.988 − 797 =
7. 7.758 − 658 =
8. 8.726 − 307 =
9. 9.786 − 429 =
10. 10.836 − 199 =
11. 11.738 − 439 =
12. 12.977 − 398 =
13. 13.559 − 297 =
14. 14.814 − 299 =
15. 15.822 − 687 =
16. 16.840 − 598 =
17. 17.310 − 187 =
18. 18.940 − 499 =
19. 19.280 − 198 =
20. 20.457 − 299 =
21. 21.777 − 598 =
22. 22.778 − 197 =
23. 23.770 − 698 =
24. 24.429 − 297 =
25. 25.746 − 587 =
26. 26.531 − 289 =
27. 27.394 − 379 =
28. 28.802 − 698 =
29. 29.861 − 797 =
30. 30.928 − 498 =
31. 31.904 − 229 =
32. 32.255 − 199 =
33. 33.431 − 297 =
34. 34.757 − 649 =
35. 35.751 − 498 =
36. 36.925 − 198 =
37. 37.297 − 199 =
38. 38.949 − 599 =
39. 39.512 − 137 =
40. 40.675 − 498 =

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