Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 935 · 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. 1.766 − 599 =
2. 2.626 − 497 =
3. 3.928 − 539 =
4. 4.697 − 598 =
5. 5.232 − 158 =
6. 6.557 − 297 =
7. 7.520 − 299 =
8. 8.865 − 518 =
9. 9.890 − 597 =
10. 10.587 − 408 =
11. 11.901 − 647 =
12. 12.480 − 298 =
13. 13.544 − 399 =
14. 14.561 − 249 =
15. 15.939 − 299 =
16. 16.697 − 597 =
17. 17.381 − 297 =
18. 18.658 − 567 =
19. 19.832 − 527 =
20. 20.353 − 198 =
21. 21.576 − 398 =
22. 22.732 − 299 =
23. 23.793 − 669 =
24. 24.642 − 349 =
25. 25.565 − 458 =
26. 26.896 − 567 =
27. 27.413 − 197 =
28. 28.848 − 799 =
29. 29.335 − 298 =
30. 30.984 − 799 =
31. 31.305 − 199 =
32. 32.886 − 697 =
33. 33.968 − 688 =
34. 34.681 − 157 =
35. 35.654 − 429 =
36. 36.693 − 568 =
37. 37.833 − 398 =
38. 38.740 − 299 =
39. 39.364 − 299 =
40. 40.717 − 297 =

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