Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 349 · 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. 1.416 − 199 =
2. 2.511 − 397 =
3. 3.722 − 297 =
4. 4.486 − 459 =
5. 5.599 − 249 =
6. 6.764 − 499 =
7. 7.315 − 299 =
8. 8.605 − 298 =
9. 9.432 − 289 =
10. 10.522 − 299 =
11. 11.703 − 198 =
12. 12.782 − 399 =
13. 13.784 − 449 =
14. 14.705 − 599 =
15. 15.491 − 297 =
16. 16.680 − 149 =
17. 17.414 − 277 =
18. 18.974 − 197 =
19. 19.617 − 198 =
20. 20.925 − 598 =
21. 21.413 − 299 =
22. 22.766 − 268 =
23. 23.911 − 398 =
24. 24.670 − 459 =
25. 25.932 − 399 =
26. 26.689 − 547 =
27. 27.907 − 799 =
28. 28.869 − 527 =
29. 29.986 − 487 =
30. 30.621 − 319 =
31. 31.374 − 299 =
32. 32.899 − 428 =
33. 33.590 − 498 =
34. 34.820 − 658 =
35. 35.996 − 299 =
36. 36.721 − 699 =
37. 37.894 − 799 =
38. 38.897 − 697 =
39. 39.950 − 219 =
40. 40.780 − 598 =

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