Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 27 · 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. 1.800 − 628 =
2. 2.545 − 298 =
3. 3.609 − 488 =
4. 4.808 − 297 =
5. 5.408 − 199 =
6. 6.665 − 499 =
7. 7.832 − 497 =
8. 8.682 − 119 =
9. 9.598 − 399 =
10. 10.933 − 599 =
11. 11.865 − 398 =
12. 12.979 − 569 =
13. 13.752 − 577 =
14. 14.358 − 197 =
15. 15.878 − 597 =
16. 16.878 − 697 =
17. 17.222 − 198 =
18. 18.969 − 397 =
19. 19.815 − 799 =
20. 20.743 − 417 =
21. 21.425 − 297 =
22. 22.534 − 318 =
23. 23.513 − 297 =
24. 24.711 − 279 =
25. 25.811 − 589 =
26. 26.722 − 499 =
27. 27.820 − 797 =
28. 28.670 − 297 =
29. 29.604 − 297 =
30. 30.773 − 198 =
31. 31.843 − 479 =
32. 32.982 − 397 =
33. 33.627 − 398 =
34. 34.651 − 468 =
35. 35.966 − 699 =
36. 36.664 − 299 =
37. 37.947 − 297 =
38. 38.969 − 499 =
39. 39.963 − 797 =
40. 40.949 − 617 =

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