Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 642 · 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. 1.876 − 577 =
2. 2.874 − 588 =
3. 3.927 − 377 =
4. 4.871 − 199 =
5. 5.726 − 167 =
6. 6.730 − 439 =
7. 7.784 − 469 =
8. 8.979 − 197 =
9. 9.960 − 429 =
10. 10.662 − 398 =
11. 11.665 − 397 =
12. 12.543 − 318 =
13. 13.963 − 459 =
14. 14.942 − 698 =
15. 15.937 − 797 =
16. 16.875 − 598 =
17. 17.985 − 198 =
18. 18.921 − 797 =
19. 19.653 − 619 =
20. 20.982 − 399 =
21. 21.843 − 798 =
22. 22.862 − 399 =
23. 23.807 − 338 =
24. 24.901 − 797 =
25. 25.625 − 198 =
26. 26.576 − 199 =
27. 27.400 − 137 =
28. 28.580 − 497 =
29. 29.805 − 199 =
30. 30.753 − 558 =
31. 31.444 − 329 =
32. 32.904 − 678 =
33. 33.747 − 397 =
34. 34.876 − 497 =
35. 35.771 − 659 =
36. 36.837 − 198 =
37. 37.929 − 259 =
38. 38.790 − 298 =
39. 39.985 − 499 =
40. 40.634 − 299 =

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