Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 285 · 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. 1.610 − 519 =
2. 2.543 − 297 =
3. 3.996 − 197 =
4. 4.156 − 138 =
5. 5.749 − 697 =
6. 6.882 − 697 =
7. 7.321 − 159 =
8. 8.482 − 299 =
9. 9.902 − 297 =
10. 10.274 − 238 =
11. 11.880 − 369 =
12. 12.687 − 197 =
13. 13.854 − 798 =
14. 14.834 − 688 =
15. 15.729 − 579 =
16. 16.600 − 298 =
17. 17.283 − 198 =
18. 18.767 − 657 =
19. 19.859 − 399 =
20. 20.808 − 397 =
21. 21.315 − 299 =
22. 22.369 − 189 =
23. 23.454 − 347 =
24. 24.624 − 519 =
25. 25.339 − 297 =
26. 26.722 − 597 =
27. 27.744 − 598 =
28. 28.439 − 289 =
29. 29.780 − 598 =
30. 30.709 − 198 =
31. 31.637 − 619 =
32. 32.548 − 449 =
33. 33.614 − 498 =
34. 34.512 − 498 =
35. 35.659 − 538 =
36. 36.907 − 799 =
37. 37.786 − 297 =
38. 38.507 − 399 =
39. 39.930 − 798 =
40. 40.904 − 668 =

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