Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 590 · 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. 1.938 − 697 =
2. 2.731 − 128 =
3. 3.816 − 288 =
4. 4.976 − 398 =
5. 5.438 − 388 =
6. 6.862 − 798 =
7. 7.430 − 399 =
8. 8.886 − 638 =
9. 9.841 − 638 =
10. 10.848 − 308 =
11. 11.697 − 597 =
12. 12.823 − 798 =
13. 13.928 − 197 =
14. 14.665 − 339 =
15. 15.425 − 129 =
16. 16.985 − 499 =
17. 17.516 − 499 =
18. 18.887 − 799 =
19. 19.766 − 648 =
20. 20.562 − 547 =
21. 21.728 − 639 =
22. 22.508 − 409 =
23. 23.847 − 637 =
24. 24.900 − 547 =
25. 25.741 − 597 =
26. 26.758 − 697 =
27. 27.388 − 198 =
28. 28.509 − 198 =
29. 29.706 − 597 =
30. 30.642 − 397 =
31. 31.992 − 207 =
32. 32.523 − 497 =
33. 33.886 − 797 =
34. 34.839 − 377 =
35. 35.967 − 598 =
36. 36.801 − 398 =
37. 37.972 − 538 =
38. 38.877 − 599 =
39. 39.704 − 299 =
40. 40.960 − 198 =

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