Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 736 · 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. 1.556 − 418 =
2. 2.946 − 199 =
3. 3.696 − 299 =
4. 4.996 − 599 =
5. 5.558 − 408 =
6. 6.667 − 399 =
7. 7.538 − 398 =
8. 8.441 − 298 =
9. 9.626 − 597 =
10. 10.992 − 478 =
11. 11.647 − 518 =
12. 12.230 − 158 =
13. 13.626 − 228 =
14. 14.952 − 199 =
15. 15.640 − 598 =
16. 16.983 − 199 =
17. 17.412 − 398 =
18. 18.849 − 797 =
19. 19.991 − 597 =
20. 20.915 − 499 =
21. 21.680 − 598 =
22. 22.790 − 208 =
23. 23.282 − 128 =
24. 24.770 − 189 =
25. 25.864 − 597 =
26. 26.714 − 198 =
27. 27.314 − 179 =
28. 28.797 − 298 =
29. 29.947 − 799 =
30. 30.796 − 187 =
31. 31.917 − 699 =
32. 32.568 − 138 =
33. 33.631 − 459 =
34. 34.811 − 499 =
35. 35.686 − 597 =
36. 36.514 − 359 =
37. 37.994 − 498 =
38. 38.693 − 298 =
39. 39.960 − 688 =
40. 40.917 − 598 =

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