Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 742 · 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. 1.351 − 229 =
2. 2.488 − 387 =
3. 3.800 − 597 =
4. 4.964 − 798 =
5. 5.676 − 297 =
6. 6.732 − 357 =
7. 7.687 − 577 =
8. 8.657 − 619 =
9. 9.740 − 358 =
10. 10.886 − 138 =
11. 11.439 − 237 =
12. 12.613 − 598 =
13. 13.688 − 177 =
14. 14.905 − 397 =
15. 15.658 − 298 =
16. 16.946 − 798 =
17. 17.780 − 367 =
18. 18.904 − 398 =
19. 19.602 − 477 =
20. 20.812 − 479 =
21. 21.799 − 398 =
22. 22.871 − 618 =
23. 23.855 − 697 =
24. 24.771 − 397 =
25. 25.773 − 697 =
26. 26.766 − 599 =
27. 27.272 − 208 =
28. 28.424 − 399 =
29. 29.716 − 268 =
30. 30.739 − 597 =
31. 31.725 − 619 =
32. 32.602 − 168 =
33. 33.417 − 137 =
34. 34.265 − 158 =
35. 35.998 − 157 =
36. 36.851 − 487 =
37. 37.976 − 797 =
38. 38.603 − 388 =
39. 39.514 − 229 =
40. 40.769 − 357 =

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