Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 588 · 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. 1.238 − 197 =
2. 2.434 − 397 =
3. 3.418 − 338 =
4. 4.904 − 238 =
5. 5.979 − 499 =
6. 6.954 − 797 =
7. 7.993 − 507 =
8. 8.751 − 697 =
9. 9.611 − 477 =
10. 10.412 − 299 =
11. 11.279 − 198 =
12. 12.578 − 437 =
13. 13.563 − 199 =
14. 14.936 − 699 =
15. 15.775 − 388 =
16. 16.919 − 799 =
17. 17.265 − 197 =
18. 18.797 − 197 =
19. 19.864 − 259 =
20. 20.970 − 799 =
21. 21.352 − 298 =
22. 22.947 − 799 =
23. 23.964 − 398 =
24. 24.637 − 279 =
25. 25.958 − 499 =
26. 26.775 − 659 =
27. 27.718 − 618 =
28. 28.512 − 248 =
29. 29.881 − 197 =
30. 30.685 − 609 =
31. 31.618 − 499 =
32. 32.475 − 387 =
33. 33.947 − 399 =
34. 34.571 − 298 =
35. 35.940 − 198 =
36. 36.799 − 298 =
37. 37.784 − 298 =
38. 38.905 − 799 =
39. 39.134 − 118 =
40. 40.379 − 197 =

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