Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 885 · 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. 1.644 − 559 =
2. 2.959 − 497 =
3. 3.864 − 697 =
4. 4.679 − 397 =
5. 5.383 − 139 =
6. 6.681 − 657 =
7. 7.967 − 209 =
8. 8.895 − 799 =
9. 9.927 − 797 =
10. 10.677 − 299 =
11. 11.487 − 397 =
12. 12.928 − 598 =
13. 13.876 − 799 =
14. 14.896 − 498 =
15. 15.821 − 378 =
16. 16.918 − 599 =
17. 17.840 − 799 =
18. 18.393 − 197 =
19. 19.611 − 169 =
20. 20.700 − 189 =
21. 21.999 − 299 =
22. 22.599 − 398 =
23. 23.702 − 598 =
24. 24.846 − 698 =
25. 25.698 − 327 =
26. 26.961 − 398 =
27. 27.237 − 207 =
28. 28.780 − 209 =
29. 29.849 − 597 =
30. 30.970 − 798 =
31. 31.907 − 299 =
32. 32.909 − 797 =
33. 33.897 − 798 =
34. 34.447 − 398 =
35. 35.241 − 197 =
36. 36.449 − 217 =
37. 37.956 − 599 =
38. 38.319 − 129 =
39. 39.886 − 498 =
40. 40.857 − 298 =

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