Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 857 · 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. 1.488 − 148 =
2. 2.811 − 698 =
3. 3.998 − 199 =
4. 4.696 − 537 =
5. 5.254 − 199 =
6. 6.725 − 638 =
7. 7.439 − 299 =
8. 8.886 − 299 =
9. 9.890 − 399 =
10. 10.918 − 438 =
11. 11.815 − 668 =
12. 12.233 − 198 =
13. 13.811 − 309 =
14. 14.529 − 197 =
15. 15.479 − 297 =
16. 16.863 − 297 =
17. 17.273 − 199 =
18. 18.475 − 299 =
19. 19.961 − 399 =
20. 20.728 − 579 =
21. 21.921 − 567 =
22. 22.766 − 609 =
23. 23.894 − 799 =
24. 24.721 − 698 =
25. 25.423 − 359 =
26. 26.862 − 299 =
27. 27.953 − 199 =
28. 28.276 − 199 =
29. 29.827 − 498 =
30. 30.770 − 398 =
31. 31.929 − 699 =
32. 32.561 − 197 =
33. 33.498 − 299 =
34. 34.982 − 599 =
35. 35.750 − 498 =
36. 36.560 − 397 =
37. 37.691 − 597 =
38. 38.908 − 619 =
39. 39.790 − 467 =
40. 40.956 − 259 =

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