Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 937 · 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. 1.575 − 399 =
2. 2.741 − 298 =
3. 3.547 − 297 =
4. 4.557 − 527 =
5. 5.975 − 297 =
6. 6.840 − 197 =
7. 7.730 − 698 =
8. 8.966 − 388 =
9. 9.499 − 198 =
10. 10.783 − 187 =
11. 11.669 − 597 =
12. 12.965 − 319 =
13. 13.925 − 397 =
14. 14.178 − 129 =
15. 15.775 − 699 =
16. 16.850 − 598 =
17. 17.951 − 518 =
18. 18.372 − 299 =
19. 19.681 − 259 =
20. 20.701 − 248 =
21. 21.960 − 387 =
22. 22.570 − 298 =
23. 23.492 − 197 =
24. 24.516 − 229 =
25. 25.416 − 157 =
26. 26.735 − 297 =
27. 27.927 − 398 =
28. 28.691 − 299 =
29. 29.954 − 199 =
30. 30.803 − 599 =
31. 31.395 − 367 =
32. 32.825 − 799 =
33. 33.702 − 597 =
34. 34.715 − 198 =
35. 35.772 − 698 =
36. 36.746 − 397 =
37. 37.891 − 399 =
38. 38.670 − 387 =
39. 39.938 − 597 =
40. 40.467 − 197 =

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