Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 692 · 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. 1.692 − 337 =
2. 2.693 − 629 =
3. 3.942 − 699 =
4. 4.934 − 597 =
5. 5.763 − 399 =
6. 6.710 − 458 =
7. 7.898 − 599 =
8. 8.356 − 147 =
9. 9.920 − 298 =
10. 10.928 − 279 =
11. 11.861 − 199 =
12. 12.764 − 199 =
13. 13.862 − 667 =
14. 14.243 − 198 =
15. 15.611 − 389 =
16. 16.895 − 238 =
17. 17.690 − 497 =
18. 18.626 − 299 =
19. 19.879 − 198 =
20. 20.639 − 297 =
21. 21.228 − 198 =
22. 22.701 − 597 =
23. 23.637 − 499 =
24. 24.843 − 418 =
25. 25.924 − 688 =
26. 26.864 − 798 =
27. 27.777 − 537 =
28. 28.277 − 167 =
29. 29.822 − 397 =
30. 30.807 − 598 =
31. 31.867 − 599 =
32. 32.320 − 198 =
33. 33.759 − 468 =
34. 34.839 − 199 =
35. 35.661 − 599 =
36. 36.890 − 799 =
37. 37.945 − 678 =
38. 38.825 − 298 =
39. 39.818 − 598 =
40. 40.943 − 567 =

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