Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 822 · 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. 1.566 − 207 =
2. 2.531 − 398 =
3. 3.917 − 799 =
4. 4.335 − 168 =
5. 5.686 − 499 =
6. 6.806 − 257 =
7. 7.871 − 698 =
8. 8.428 − 279 =
9. 9.304 − 199 =
10. 10.648 − 308 =
11. 11.788 − 698 =
12. 12.709 − 679 =
13. 13.776 − 499 =
14. 14.842 − 609 =
15. 15.839 − 197 =
16. 16.341 − 119 =
17. 17.904 − 598 =
18. 18.809 − 398 =
19. 19.310 − 199 =
20. 20.869 − 199 =
21. 21.343 − 308 =
22. 22.684 − 498 =
23. 23.440 − 299 =
24. 24.980 − 599 =
25. 25.394 − 297 =
26. 26.838 − 577 =
27. 27.448 − 397 =
28. 28.789 − 277 =
29. 29.710 − 269 =
30. 30.876 − 258 =
31. 31.797 − 507 =
32. 32.163 − 127 =
33. 33.962 − 498 =
34. 34.498 − 448 =
35. 35.540 − 339 =
36. 36.780 − 299 =
37. 37.894 − 679 =
38. 38.695 − 399 =
39. 39.341 − 247 =
40. 40.650 − 278 =

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