Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 104 · 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. 1.606 − 577 =
2. 2.954 − 687 =
3. 3.717 − 668 =
4. 4.688 − 337 =
5. 5.890 − 549 =
6. 6.816 − 438 =
7. 7.908 − 699 =
8. 8.886 − 218 =
9. 9.868 − 698 =
10. 10.918 − 658 =
11. 11.895 − 597 =
12. 12.749 − 367 =
13. 13.683 − 597 =
14. 14.406 − 299 =
15. 15.611 − 589 =
16. 16.890 − 627 =
17. 17.865 − 399 =
18. 18.349 − 197 =
19. 19.728 − 498 =
20. 20.924 − 238 =
21. 21.968 − 397 =
22. 22.242 − 197 =
23. 23.817 − 699 =
24. 24.680 − 378 =
25. 25.611 − 497 =
26. 26.652 − 389 =
27. 27.423 − 197 =
28. 28.818 − 197 =
29. 29.637 − 418 =
30. 30.935 − 797 =
31. 31.948 − 398 =
32. 32.826 − 399 =
33. 33.929 − 797 =
34. 34.810 − 139 =
35. 35.908 − 397 =
36. 36.611 − 259 =
37. 37.745 − 629 =
38. 38.472 − 299 =
39. 39.311 − 198 =
40. 40.851 − 498 =

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