Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 543 · 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. 1.707 − 597 =
2. 2.864 − 308 =
3. 3.855 − 797 =
4. 4.649 − 199 =
5. 5.723 − 399 =
6. 6.828 − 199 =
7. 7.753 − 687 =
8. 8.885 − 557 =
9. 9.833 − 798 =
10. 10.772 − 658 =
11. 11.323 − 149 =
12. 12.595 − 219 =
13. 13.842 − 117 =
14. 14.771 − 697 =
15. 15.836 − 379 =
16. 16.846 − 297 =
17. 17.815 − 367 =
18. 18.646 − 577 =
19. 19.740 − 338 =
20. 20.546 − 158 =
21. 21.409 − 129 =
22. 22.831 − 797 =
23. 23.395 − 309 =
24. 24.730 − 697 =
25. 25.956 − 799 =
26. 26.882 − 797 =
27. 27.935 − 659 =
28. 28.848 − 407 =
29. 29.715 − 697 =
30. 30.911 − 399 =
31. 31.844 − 697 =
32. 32.536 − 347 =
33. 33.633 − 529 =
34. 34.460 − 297 =
35. 35.721 − 399 =
36. 36.747 − 659 =
37. 37.612 − 397 =
38. 38.902 − 198 =
39. 39.801 − 299 =
40. 40.955 − 698 =

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