Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 630 · 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. 1.976 − 697 =
2. 2.201 − 138 =
3. 3.944 − 699 =
4. 4.906 − 548 =
5. 5.581 − 499 =
6. 6.588 − 167 =
7. 7.356 − 199 =
8. 8.454 − 397 =
9. 9.478 − 199 =
10. 10.657 − 399 =
11. 11.664 − 297 =
12. 12.903 − 639 =
13. 13.555 − 509 =
14. 14.823 − 798 =
15. 15.370 − 227 =
16. 16.771 − 399 =
17. 17.626 − 198 =
18. 18.722 − 249 =
19. 19.910 − 799 =
20. 20.405 − 377 =
21. 21.845 − 328 =
22. 22.575 − 349 =
23. 23.441 − 399 =
24. 24.937 − 678 =
25. 25.949 − 657 =
26. 26.819 − 639 =
27. 27.924 − 497 =
28. 28.593 − 299 =
29. 29.884 − 657 =
30. 30.325 − 297 =
31. 31.669 − 519 =
32. 32.955 − 499 =
33. 33.826 − 677 =
34. 34.977 − 697 =
35. 35.586 − 299 =
36. 36.964 − 797 =
37. 37.554 − 298 =
38. 38.743 − 597 =
39. 39.630 − 198 =
40. 40.601 − 477 =

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