Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 696 · 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. 1.675 − 369 =
2. 2.715 − 699 =
3. 3.962 − 307 =
4. 4.847 − 197 =
5. 5.843 − 297 =
6. 6.912 − 797 =
7. 7.925 − 539 =
8. 8.867 − 497 =
9. 9.660 − 597 =
10. 10.830 − 359 =
11. 11.724 − 699 =
12. 12.783 − 497 =
13. 13.840 − 597 =
14. 14.700 − 437 =
15. 15.869 − 447 =
16. 16.496 − 198 =
17. 17.550 − 159 =
18. 18.931 − 799 =
19. 19.979 − 699 =
20. 20.949 − 297 =
21. 21.287 − 149 =
22. 22.849 − 799 =
23. 23.944 − 697 =
24. 24.432 − 199 =
25. 25.873 − 698 =
26. 26.946 − 199 =
27. 27.433 − 277 =
28. 28.993 − 188 =
29. 29.936 − 498 =
30. 30.790 − 497 =
31. 31.399 − 299 =
32. 32.432 − 218 =
33. 33.723 − 277 =
34. 34.876 − 699 =
35. 35.681 − 299 =
36. 36.819 − 478 =
37. 37.906 − 699 =
38. 38.628 − 599 =
39. 39.525 − 458 =
40. 40.628 − 598 =

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