Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 537 · 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. 1.883 − 398 =
2. 2.959 − 299 =
3. 3.815 − 478 =
4. 4.997 − 698 =
5. 5.818 − 498 =
6. 6.474 − 437 =
7. 7.901 − 267 =
8. 8.672 − 399 =
9. 9.634 − 279 =
10. 10.742 − 498 =
11. 11.942 − 299 =
12. 12.887 − 799 =
13. 13.829 − 189 =
14. 14.998 − 479 =
15. 15.903 − 798 =
16. 16.685 − 629 =
17. 17.733 − 699 =
18. 18.780 − 199 =
19. 19.718 − 369 =
20. 20.557 − 399 =
21. 21.626 − 589 =
22. 22.491 − 199 =
23. 23.684 − 229 =
24. 24.974 − 699 =
25. 25.908 − 328 =
26. 26.727 − 699 =
27. 27.520 − 397 =
28. 28.634 − 198 =
29. 29.424 − 299 =
30. 30.469 − 217 =
31. 31.698 − 199 =
32. 32.803 − 417 =
33. 33.775 − 598 =
34. 34.418 − 149 =
35. 35.541 − 408 =
36. 36.619 − 598 =
37. 37.953 − 697 =
38. 38.832 − 797 =
39. 39.876 − 258 =
40. 40.827 − 799 =

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