Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 495 · 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. 1.547 − 498 =
2. 2.675 − 329 =
3. 3.761 − 669 =
4. 4.185 − 137 =
5. 5.815 − 597 =
6. 6.787 − 667 =
7. 7.842 − 599 =
8. 8.733 − 297 =
9. 9.761 − 697 =
10. 10.402 − 297 =
11. 11.474 − 279 =
12. 12.816 − 659 =
13. 13.815 − 197 =
14. 14.968 − 599 =
15. 15.933 − 499 =
16. 16.710 − 198 =
17. 17.930 − 448 =
18. 18.859 − 397 =
19. 19.868 − 797 =
20. 20.651 − 409 =
21. 21.715 − 649 =
22. 22.669 − 587 =
23. 23.824 − 597 =
24. 24.826 − 428 =
25. 25.980 − 598 =
26. 26.333 − 297 =
27. 27.934 − 697 =
28. 28.834 − 297 =
29. 29.854 − 517 =
30. 30.673 − 469 =
31. 31.351 − 179 =
32. 32.853 − 797 =
33. 33.726 − 658 =
34. 34.832 − 128 =
35. 35.504 − 397 =
36. 36.941 − 678 =
37. 37.590 − 197 =
38. 38.781 − 399 =
39. 39.848 − 478 =
40. 40.757 − 598 =

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