Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 358 · 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. 1.353 − 307 =
2. 2.326 − 248 =
3. 3.946 − 597 =
4. 4.910 − 299 =
5. 5.926 − 619 =
6. 6.676 − 397 =
7. 7.862 − 699 =
8. 8.772 − 698 =
9. 9.882 − 198 =
10. 10.876 − 797 =
11. 11.584 − 328 =
12. 12.900 − 359 =
13. 13.600 − 198 =
14. 14.879 − 248 =
15. 15.665 − 519 =
16. 16.766 − 599 =
17. 17.566 − 199 =
18. 18.486 − 399 =
19. 19.437 − 299 =
20. 20.986 − 297 =
21. 21.911 − 797 =
22. 22.958 − 798 =
23. 23.608 − 399 =
24. 24.768 − 468 =
25. 25.926 − 537 =
26. 26.554 − 298 =
27. 27.568 − 499 =
28. 28.660 − 497 =
29. 29.749 − 477 =
30. 30.766 − 598 =
31. 31.892 − 597 =
32. 32.720 − 557 =
33. 33.540 − 258 =
34. 34.619 − 399 =
35. 35.520 − 307 =
36. 36.864 − 498 =
37. 37.929 − 399 =
38. 38.796 − 668 =
39. 39.883 − 299 =
40. 40.553 − 509 =

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