Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 672 · 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. 1.481 − 408 =
2. 2.993 − 798 =
3. 3.459 − 298 =
4. 4.949 − 627 =
5. 5.531 − 298 =
6. 6.383 − 329 =
7. 7.843 − 599 =
8. 8.779 − 508 =
9. 9.561 − 398 =
10. 10.890 − 699 =
11. 11.972 − 219 =
12. 12.375 − 198 =
13. 13.876 − 219 =
14. 14.817 − 138 =
15. 15.996 − 799 =
16. 16.676 − 298 =
17. 17.876 − 799 =
18. 18.418 − 299 =
19. 19.990 − 319 =
20. 20.978 − 448 =
21. 21.921 − 797 =
22. 22.580 − 279 =
23. 23.674 − 377 =
24. 24.586 − 299 =
25. 25.647 − 628 =
26. 26.979 − 798 =
27. 27.764 − 697 =
28. 28.878 − 798 =
29. 29.993 − 559 =
30. 30.818 − 649 =
31. 31.463 − 199 =
32. 32.693 − 657 =
33. 33.704 − 588 =
34. 34.909 − 399 =
35. 35.326 − 197 =
36. 36.310 − 197 =
37. 37.715 − 697 =
38. 38.612 − 499 =
39. 39.726 − 699 =
40. 40.575 − 497 =

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