Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 873 · 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. 1.773 − 399 =
2. 2.746 − 558 =
3. 3.326 − 299 =
4. 4.984 − 199 =
5. 5.443 − 408 =
6. 6.327 − 119 =
7. 7.355 − 127 =
8. 8.844 − 699 =
9. 9.422 − 309 =
10. 10.974 − 797 =
11. 11.735 − 497 =
12. 12.867 − 799 =
13. 13.518 − 398 =
14. 14.655 − 409 =
15. 15.840 − 197 =
16. 16.690 − 659 =
17. 17.853 − 798 =
18. 18.386 − 199 =
19. 19.678 − 237 =
20. 20.884 − 798 =
21. 21.682 − 598 =
22. 22.812 − 797 =
23. 23.952 − 199 =
24. 24.664 − 498 =
25. 25.585 − 159 =
26. 26.926 − 517 =
27. 27.513 − 458 =
28. 28.944 − 218 =
29. 29.756 − 349 =
30. 30.494 − 397 =
31. 31.943 − 797 =
32. 32.812 − 799 =
33. 33.834 − 699 =
34. 34.737 − 599 =
35. 35.881 − 799 =
36. 36.942 − 197 =
37. 37.923 − 498 =
38. 38.704 − 489 =
39. 39.857 − 299 =
40. 40.905 − 439 =

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