Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 362 · 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. 1.512 − 197 =
2. 2.767 − 548 =
3. 3.976 − 799 =
4. 4.457 − 167 =
5. 5.778 − 199 =
6. 6.809 − 589 =
7. 7.980 − 698 =
8. 8.802 − 697 =
9. 9.364 − 209 =
10. 10.218 − 169 =
11. 11.438 − 197 =
12. 12.765 − 489 =
13. 13.550 − 138 =
14. 14.777 − 597 =
15. 15.471 − 399 =
16. 16.875 − 497 =
17. 17.946 − 259 =
18. 18.916 − 497 =
19. 19.903 − 598 =
20. 20.837 − 699 =
21. 21.845 − 367 =
22. 22.822 − 499 =
23. 23.873 − 498 =
24. 24.754 − 229 =
25. 25.660 − 308 =
26. 26.927 − 799 =
27. 27.340 − 179 =
28. 28.851 − 658 =
29. 29.730 − 197 =
30. 30.704 − 619 =
31. 31.732 − 398 =
32. 32.573 − 508 =
33. 33.865 − 568 =
34. 34.890 − 698 =
35. 35.928 − 298 =
36. 36.414 − 148 =
37. 37.522 − 199 =
38. 38.697 − 597 =
39. 39.958 − 667 =
40. 40.933 − 797 =

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