Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 944 · 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. 1.853 − 598 =
2. 2.928 − 248 =
3. 3.956 − 529 =
4. 4.940 − 798 =
5. 5.958 − 438 =
6. 6.630 − 147 =
7. 7.855 − 797 =
8. 8.756 − 499 =
9. 9.513 − 398 =
10. 10.668 − 617 =
11. 11.767 − 447 =
12. 12.799 − 599 =
13. 13.524 − 258 =
14. 14.991 − 698 =
15. 15.846 − 489 =
16. 16.925 − 799 =
17. 17.441 − 198 =
18. 18.719 − 588 =
19. 19.570 − 197 =
20. 20.866 − 799 =
21. 21.632 − 199 =
22. 22.504 − 119 =
23. 23.489 − 299 =
24. 24.585 − 499 =
25. 25.735 − 287 =
26. 26.878 − 577 =
27. 27.664 − 599 =
28. 28.469 − 398 =
29. 29.756 − 297 =
30. 30.796 − 299 =
31. 31.685 − 348 =
32. 32.712 − 177 =
33. 33.966 − 199 =
34. 34.654 − 597 =
35. 35.534 − 288 =
36. 36.552 − 499 =
37. 37.669 − 199 =
38. 38.760 − 599 =
39. 39.619 − 469 =
40. 40.680 − 299 =

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