Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 511 · 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. 1.740 − 397 =
2. 2.821 − 449 =
3. 3.743 − 699 =
4. 4.830 − 699 =
5. 5.591 − 497 =
6. 6.893 − 198 =
7. 7.686 − 199 =
8. 8.714 − 227 =
9. 9.344 − 197 =
10. 10.732 − 698 =
11. 11.606 − 449 =
12. 12.820 − 597 =
13. 13.713 − 568 =
14. 14.847 − 568 =
15. 15.767 − 599 =
16. 16.557 − 398 =
17. 17.538 − 199 =
18. 18.328 − 299 =
19. 19.763 − 477 =
20. 20.467 − 299 =
21. 21.869 − 408 =
22. 22.894 − 187 =
23. 23.703 − 549 =
24. 24.840 − 518 =
25. 25.600 − 229 =
26. 26.851 − 498 =
27. 27.533 − 397 =
28. 28.571 − 439 =
29. 29.568 − 198 =
30. 30.446 − 399 =
31. 31.880 − 467 =
32. 32.601 − 499 =
33. 33.974 − 639 =
34. 34.674 − 469 =
35. 35.539 − 498 =
36. 36.963 − 497 =
37. 37.936 − 797 =
38. 38.774 − 378 =
39. 39.850 − 798 =
40. 40.960 − 457 =

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