Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 957 · 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. 1.931 − 368 =
2. 2.854 − 667 =
3. 3.812 − 599 =
4. 4.925 − 307 =
5. 5.685 − 299 =
6. 6.874 − 599 =
7. 7.461 − 247 =
8. 8.472 − 368 =
9. 9.576 − 297 =
10. 10.548 − 329 =
11. 11.889 − 569 =
12. 12.852 − 797 =
13. 13.793 − 219 =
14. 14.483 − 467 =
15. 15.829 − 697 =
16. 16.839 − 497 =
17. 17.663 − 598 =
18. 18.494 − 397 =
19. 19.705 − 587 =
20. 20.395 − 199 =
21. 21.793 − 168 =
22. 22.954 − 699 =
23. 23.454 − 198 =
24. 24.442 − 209 =
25. 25.946 − 267 =
26. 26.860 − 798 =
27. 27.939 − 497 =
28. 28.908 − 598 =
29. 29.648 − 118 =
30. 30.668 − 499 =
31. 31.937 − 689 =
32. 32.477 − 297 =
33. 33.967 − 419 =
34. 34.367 − 297 =
35. 35.496 − 147 =
36. 36.819 − 218 =
37. 37.885 − 799 =
38. 38.864 − 239 =
39. 39.582 − 567 =
40. 40.412 − 397 =

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