Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 521 · 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. 1.744 − 698 =
2. 2.869 − 669 =
3. 3.394 − 379 =
4. 4.591 − 499 =
5. 5.984 − 578 =
6. 6.842 − 297 =
7. 7.282 − 157 =
8. 8.988 − 798 =
9. 9.881 − 797 =
10. 10.992 − 697 =
11. 11.862 − 697 =
12. 12.912 − 419 =
13. 13.742 − 397 =
14. 14.922 − 497 =
15. 15.893 − 398 =
16. 16.879 − 297 =
17. 17.911 − 799 =
18. 18.324 − 189 =
19. 19.406 − 299 =
20. 20.854 − 599 =
21. 21.791 − 697 =
22. 22.557 − 299 =
23. 23.217 − 159 =
24. 24.670 − 507 =
25. 25.940 − 798 =
26. 26.418 − 359 =
27. 27.940 − 797 =
28. 28.727 − 499 =
29. 29.787 − 527 =
30. 30.306 − 158 =
31. 31.797 − 169 =
32. 32.847 − 598 =
33. 33.863 − 409 =
34. 34.727 − 299 =
35. 35.893 − 797 =
36. 36.896 − 398 =
37. 37.675 − 489 =
38. 38.530 − 337 =
39. 39.851 − 309 =
40. 40.738 − 598 =

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