Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 475 · 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. 1.849 − 489 =
2. 2.431 − 397 =
3. 3.815 − 639 =
4. 4.501 − 368 =
5. 5.882 − 248 =
6. 6.343 − 307 =
7. 7.547 − 497 =
8. 8.618 − 579 =
9. 9.745 − 399 =
10. 10.801 − 499 =
11. 11.445 − 199 =
12. 12.789 − 199 =
13. 13.696 − 239 =
14. 14.436 − 299 =
15. 15.775 − 417 =
16. 16.696 − 299 =
17. 17.808 − 697 =
18. 18.755 − 527 =
19. 19.768 − 698 =
20. 20.846 − 399 =
21. 21.566 − 118 =
22. 22.420 − 297 =
23. 23.885 − 698 =
24. 24.674 − 398 =
25. 25.626 − 397 =
26. 26.991 − 497 =
27. 27.632 − 499 =
28. 28.839 − 397 =
29. 29.951 − 199 =
30. 30.638 − 287 =
31. 31.695 − 599 =
32. 32.843 − 598 =
33. 33.916 − 299 =
34. 34.482 − 279 =
35. 35.982 − 699 =
36. 36.694 − 499 =
37. 37.994 − 797 =
38. 38.719 − 188 =
39. 39.376 − 298 =
40. 40.543 − 218 =

Free mental maths lessons, practice and worksheets at talentjr.in/mental-maths