Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 529 · 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. 1.653 − 398 =
2. 2.885 − 698 =
3. 3.684 − 487 =
4. 4.603 − 298 =
5. 5.991 − 797 =
6. 6.753 − 278 =
7. 7.549 − 197 =
8. 8.951 − 297 =
9. 9.865 − 588 =
10. 10.876 − 797 =
11. 11.643 − 599 =
12. 12.484 − 297 =
13. 13.854 − 399 =
14. 14.496 − 218 =
15. 15.862 − 799 =
16. 16.916 − 559 =
17. 17.853 − 699 =
18. 18.733 − 198 =
19. 19.982 − 599 =
20. 20.794 − 558 =
21. 21.844 − 699 =
22. 22.736 − 199 =
23. 23.307 − 258 =
24. 24.512 − 498 =
25. 25.465 − 158 =
26. 26.948 − 799 =
27. 27.963 − 118 =
28. 28.809 − 198 =
29. 29.744 − 419 =
30. 30.541 − 399 =
31. 31.758 − 297 =
32. 32.929 − 677 =
33. 33.841 − 199 =
34. 34.917 − 799 =
35. 35.554 − 428 =
36. 36.563 − 467 =
37. 37.882 − 797 =
38. 38.902 − 297 =
39. 39.965 − 388 =
40. 40.453 − 299 =

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