Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 961 · 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. 1.717 − 598 =
2. 2.388 − 357 =
3. 3.938 − 798 =
4. 4.812 − 699 =
5. 5.740 − 399 =
6. 6.721 − 269 =
7. 7.541 − 299 =
8. 8.563 − 399 =
9. 9.943 − 399 =
10. 10.793 − 697 =
11. 11.855 − 699 =
12. 12.960 − 697 =
13. 13.680 − 199 =
14. 14.924 − 798 =
15. 15.719 − 397 =
16. 16.517 − 497 =
17. 17.832 − 497 =
18. 18.910 − 399 =
19. 19.759 − 198 =
20. 20.443 − 399 =
21. 21.732 − 418 =
22. 22.405 − 298 =
23. 23.808 − 347 =
24. 24.978 − 598 =
25. 25.675 − 199 =
26. 26.828 − 798 =
27. 27.842 − 167 =
28. 28.297 − 218 =
29. 29.992 − 499 =
30. 30.540 − 457 =
31. 31.633 − 319 =
32. 32.591 − 199 =
33. 33.896 − 198 =
34. 34.834 − 638 =
35. 35.837 − 399 =
36. 36.289 − 158 =
37. 37.313 − 298 =
38. 38.546 − 227 =
39. 39.870 − 598 =
40. 40.907 − 698 =

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