Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 322 · 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. 1.875 − 599 =
2. 2.730 − 649 =
3. 3.743 − 297 =
4. 4.959 − 697 =
5. 5.554 − 409 =
6. 6.710 − 399 =
7. 7.933 − 399 =
8. 8.645 − 368 =
9. 9.973 − 498 =
10. 10.790 − 659 =
11. 11.939 − 599 =
12. 12.883 − 698 =
13. 13.444 − 299 =
14. 14.993 − 259 =
15. 15.938 − 529 =
16. 16.725 − 148 =
17. 17.939 − 698 =
18. 18.461 − 328 =
19. 19.864 − 698 =
20. 20.830 − 799 =
21. 21.745 − 579 =
22. 22.879 − 797 =
23. 23.895 − 799 =
24. 24.633 − 499 =
25. 25.801 − 528 =
26. 26.805 − 628 =
27. 27.835 − 697 =
28. 28.558 − 198 =
29. 29.807 − 399 =
30. 30.988 − 607 =
31. 31.814 − 697 =
32. 32.964 − 799 =
33. 33.627 − 339 =
34. 34.795 − 629 =
35. 35.664 − 477 =
36. 36.612 − 297 =
37. 37.868 − 227 =
38. 38.658 − 277 =
39. 39.467 − 419 =
40. 40.855 − 458 =

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