Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 973 · 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. 1.397 − 369 =
2. 2.461 − 399 =
3. 3.982 − 317 =
4. 4.875 − 199 =
5. 5.985 − 699 =
6. 6.802 − 399 =
7. 7.671 − 307 =
8. 8.632 − 297 =
9. 9.966 − 559 =
10. 10.625 − 389 =
11. 11.733 − 498 =
12. 12.578 − 197 =
13. 13.706 − 597 =
14. 14.400 − 269 =
15. 15.595 − 197 =
16. 16.748 − 197 =
17. 17.992 − 497 =
18. 18.876 − 209 =
19. 19.300 − 197 =
20. 20.836 − 569 =
21. 21.799 − 337 =
22. 22.721 − 288 =
23. 23.842 − 497 =
24. 24.706 − 579 =
25. 25.615 − 599 =
26. 26.723 − 609 =
27. 27.930 − 497 =
28. 28.301 − 148 =
29. 29.630 − 479 =
30. 30.659 − 497 =
31. 31.822 − 799 =
32. 32.631 − 299 =
33. 33.496 − 299 =
34. 34.825 − 798 =
35. 35.896 − 529 =
36. 36.860 − 698 =
37. 37.955 − 388 =
38. 38.702 − 648 =
39. 39.866 − 618 =
40. 40.942 − 597 =

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