Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 662 · 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. 1.887 − 298 =
2. 2.427 − 409 =
3. 3.518 − 317 =
4. 4.932 − 557 =
5. 5.808 − 599 =
6. 6.687 − 619 =
7. 7.848 − 797 =
8. 8.799 − 198 =
9. 9.895 − 527 =
10. 10.924 − 197 =
11. 11.777 − 597 =
12. 12.604 − 368 =
13. 13.500 − 367 =
14. 14.434 − 299 =
15. 15.990 − 298 =
16. 16.991 − 599 =
17. 17.448 − 298 =
18. 18.754 − 688 =
19. 19.654 − 268 =
20. 20.941 − 799 =
21. 21.944 − 197 =
22. 22.214 − 197 =
23. 23.612 − 439 =
24. 24.615 − 587 =
25. 25.969 − 799 =
26. 26.363 − 298 =
27. 27.873 − 599 =
28. 28.837 − 478 =
29. 29.743 − 297 =
30. 30.433 − 188 =
31. 31.911 − 499 =
32. 32.652 − 397 =
33. 33.195 − 179 =
34. 34.586 − 169 =
35. 35.989 − 248 =
36. 36.455 − 299 =
37. 37.933 − 517 =
38. 38.703 − 348 =
39. 39.984 − 669 =
40. 40.840 − 797 =

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