Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 274 · 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. 1.583 − 399 =
2. 2.845 − 797 =
3. 3.993 − 699 =
4. 4.816 − 497 =
5. 5.831 − 797 =
6. 6.765 − 399 =
7. 7.563 − 197 =
8. 8.856 − 799 =
9. 9.869 − 167 =
10. 10.950 − 429 =
11. 11.918 − 698 =
12. 12.868 − 297 =
13. 13.949 − 397 =
14. 14.897 − 397 =
15. 15.750 − 697 =
16. 16.459 − 198 =
17. 17.974 − 497 =
18. 18.967 − 698 =
19. 19.819 − 647 =
20. 20.837 − 699 =
21. 21.654 − 499 =
22. 22.534 − 329 =
23. 23.787 − 508 =
24. 24.791 − 169 =
25. 25.661 − 349 =
26. 26.964 − 299 =
27. 27.482 − 299 =
28. 28.578 − 297 =
29. 29.364 − 319 =
30. 30.705 − 687 =
31. 31.725 − 487 =
32. 32.527 − 368 =
33. 33.983 − 499 =
34. 34.807 − 687 =
35. 35.516 − 198 =
36. 36.869 − 799 =
37. 37.833 − 599 =
38. 38.796 − 699 =
39. 39.890 − 697 =
40. 40.694 − 337 =

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