Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 471 · 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. 1.904 − 697 =
2. 2.942 − 608 =
3. 3.816 − 487 =
4. 4.488 − 318 =
5. 5.635 − 498 =
6. 6.743 − 698 =
7. 7.744 − 447 =
8. 8.793 − 697 =
9. 9.760 − 597 =
10. 10.964 − 167 =
11. 11.925 − 558 =
12. 12.682 − 499 =
13. 13.694 − 529 =
14. 14.770 − 397 =
15. 15.864 − 798 =
16. 16.705 − 497 =
17. 17.958 − 599 =
18. 18.602 − 429 =
19. 19.384 − 267 =
20. 20.720 − 599 =
21. 21.627 − 178 =
22. 22.766 − 668 =
23. 23.551 − 357 =
24. 24.925 − 799 =
25. 25.772 − 598 =
26. 26.965 − 498 =
27. 27.445 − 227 =
28. 28.836 − 479 =
29. 29.515 − 199 =
30. 30.881 − 598 =
31. 31.625 − 599 =
32. 32.893 − 697 =
33. 33.614 − 199 =
34. 34.975 − 678 =
35. 35.653 − 197 =
36. 36.585 − 338 =
37. 37.535 − 429 =
38. 38.969 − 797 =
39. 39.471 − 379 =
40. 40.241 − 198 =

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