Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 209 · 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. 1.745 − 498 =
2. 2.578 − 417 =
3. 3.828 − 247 =
4. 4.969 − 797 =
5. 5.263 − 188 =
6. 6.891 − 698 =
7. 7.891 − 498 =
8. 8.902 − 138 =
9. 9.697 − 469 =
10. 10.933 − 159 =
11. 11.693 − 597 =
12. 12.648 − 617 =
13. 13.894 − 548 =
14. 14.734 − 597 =
15. 15.664 − 188 =
16. 16.754 − 438 =
17. 17.900 − 697 =
18. 18.771 − 298 =
19. 19.371 − 339 =
20. 20.466 − 397 =
21. 21.287 − 169 =
22. 22.514 − 499 =
23. 23.912 − 797 =
24. 24.563 − 198 =
25. 25.843 − 597 =
26. 26.605 − 549 =
27. 27.406 − 199 =
28. 28.923 − 199 =
29. 29.778 − 599 =
30. 30.812 − 697 =
31. 31.688 − 117 =
32. 32.895 − 297 =
33. 33.480 − 287 =
34. 34.905 − 799 =
35. 35.789 − 118 =
36. 36.619 − 519 =
37. 37.841 − 407 =
38. 38.863 − 308 =
39. 39.830 − 797 =
40. 40.574 − 499 =

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