Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 903 · 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. 1.388 − 317 =
2. 2.734 − 168 =
3. 3.954 − 697 =
4. 4.846 − 509 =
5. 5.728 − 399 =
6. 6.875 − 498 =
7. 7.585 − 569 =
8. 8.677 − 567 =
9. 9.728 − 398 =
10. 10.953 − 379 =
11. 11.527 − 298 =
12. 12.763 − 329 =
13. 13.978 − 299 =
14. 14.330 − 298 =
15. 15.454 − 389 =
16. 16.799 − 297 =
17. 17.435 − 299 =
18. 18.415 − 258 =
19. 19.966 − 797 =
20. 20.671 − 597 =
21. 21.345 − 299 =
22. 22.866 − 798 =
23. 23.857 − 537 =
24. 24.760 − 248 =
25. 25.464 − 348 =
26. 26.571 − 157 =
27. 27.264 − 139 =
28. 28.486 − 297 =
29. 29.803 − 428 =
30. 30.921 − 698 =
31. 31.535 − 517 =
32. 32.518 − 119 =
33. 33.758 − 497 =
34. 34.248 − 127 =
35. 35.887 − 698 =
36. 36.800 − 509 =
37. 37.473 − 188 =
38. 38.837 − 398 =
39. 39.831 − 298 =
40. 40.811 − 217 =

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