Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 64 · 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. 1.584 − 488 =
2. 2.756 − 698 =
3. 3.940 − 697 =
4. 4.580 − 117 =
5. 5.587 − 499 =
6. 6.821 − 597 =
7. 7.686 − 498 =
8. 8.918 − 419 =
9. 9.571 − 197 =
10. 10.996 − 129 =
11. 11.629 − 598 =
12. 12.999 − 357 =
13. 13.934 − 697 =
14. 14.730 − 399 =
15. 15.950 − 678 =
16. 16.704 − 537 =
17. 17.635 − 197 =
18. 18.990 − 797 =
19. 19.915 − 799 =
20. 20.999 − 799 =
21. 21.794 − 599 =
22. 22.462 − 217 =
23. 23.634 − 597 =
24. 24.786 − 119 =
25. 25.579 − 519 =
26. 26.778 − 608 =
27. 27.580 − 307 =
28. 28.232 − 197 =
29. 29.942 − 648 =
30. 30.655 − 597 =
31. 31.832 − 599 =
32. 32.611 − 259 =
33. 33.687 − 499 =
34. 34.782 − 678 =
35. 35.457 − 309 =
36. 36.212 − 128 =
37. 37.883 − 199 =
38. 38.888 − 597 =
39. 39.935 − 797 =
40. 40.859 − 299 =

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