Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 617 · 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. 1.838 − 797 =
2. 2.406 − 299 =
3. 3.935 − 488 =
4. 4.668 − 439 =
5. 5.965 − 197 =
6. 6.727 − 698 =
7. 7.715 − 677 =
8. 8.583 − 499 =
9. 9.617 − 598 =
10. 10.575 − 399 =
11. 11.941 − 697 =
12. 12.844 − 698 =
13. 13.849 − 297 =
14. 14.696 − 499 =
15. 15.719 − 477 =
16. 16.960 − 299 =
17. 17.777 − 679 =
18. 18.882 − 339 =
19. 19.997 − 538 =
20. 20.626 − 398 =
21. 21.922 − 597 =
22. 22.316 − 189 =
23. 23.729 − 597 =
24. 24.974 − 698 =
25. 25.607 − 497 =
26. 26.576 − 299 =
27. 27.484 − 399 =
28. 28.479 − 377 =
29. 29.909 − 398 =
30. 30.999 − 408 =
31. 31.810 − 199 =
32. 32.678 − 397 =
33. 33.843 − 239 =
34. 34.407 − 199 =
35. 35.718 − 409 =
36. 36.982 − 599 =
37. 37.549 − 197 =
38. 38.633 − 499 =
39. 39.709 − 359 =
40. 40.647 − 339 =

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