Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 45 · 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. 1.663 − 398 =
2. 2.862 − 569 =
3. 3.713 − 138 =
4. 4.275 − 199 =
5. 5.994 − 128 =
6. 6.621 − 599 =
7. 7.947 − 279 =
8. 8.276 − 197 =
9. 9.282 − 258 =
10. 10.716 − 599 =
11. 11.567 − 399 =
12. 12.673 − 599 =
13. 13.298 − 197 =
14. 14.990 − 497 =
15. 15.889 − 639 =
16. 16.896 − 527 =
17. 17.872 − 639 =
18. 18.859 − 499 =
19. 19.400 − 219 =
20. 20.383 − 368 =
21. 21.671 − 199 =
22. 22.945 − 659 =
23. 23.739 − 699 =
24. 24.753 − 698 =
25. 25.703 − 678 =
26. 26.664 − 499 =
27. 27.615 − 269 =
28. 28.693 − 337 =
29. 29.631 − 597 =
30. 30.987 − 497 =
31. 31.849 − 699 =
32. 32.945 − 487 =
33. 33.423 − 299 =
34. 34.637 − 179 =
35. 35.773 − 459 =
36. 36.988 − 527 =
37. 37.737 − 127 =
38. 38.770 − 699 =
39. 39.657 − 398 =
40. 40.955 − 199 =

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