Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 237 · 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. 1.781 − 597 =
2. 2.746 − 498 =
3. 3.554 − 167 =
4. 4.888 − 578 =
5. 5.699 − 397 =
6. 6.932 − 297 =
7. 7.264 − 187 =
8. 8.843 − 598 =
9. 9.858 − 289 =
10. 10.680 − 649 =
11. 11.698 − 658 =
12. 12.592 − 357 =
13. 13.923 − 598 =
14. 14.767 − 697 =
15. 15.500 − 247 =
16. 16.676 − 499 =
17. 17.783 − 699 =
18. 18.875 − 299 =
19. 19.782 − 668 =
20. 20.947 − 798 =
21. 21.952 − 658 =
22. 22.724 − 567 =
23. 23.761 − 448 =
24. 24.174 − 128 =
25. 25.401 − 168 =
26. 26.452 − 198 =
27. 27.854 − 629 =
28. 28.631 − 598 =
29. 29.482 − 399 =
30. 30.677 − 277 =
31. 31.643 − 607 =
32. 32.599 − 169 =
33. 33.517 − 497 =
34. 34.749 − 488 =
35. 35.954 − 599 =
36. 36.386 − 239 =
37. 37.880 − 598 =
38. 38.826 − 687 =
39. 39.444 − 397 =
40. 40.505 − 279 =

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