Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 380 · 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. 1.580 − 448 =
2. 2.722 − 399 =
3. 3.814 − 797 =
4. 4.751 − 387 =
5. 5.229 − 167 =
6. 6.954 − 797 =
7. 7.631 − 498 =
8. 8.344 − 199 =
9. 9.485 − 298 =
10. 10.859 − 607 =
11. 11.991 − 498 =
12. 12.772 − 679 =
13. 13.803 − 499 =
14. 14.366 − 349 =
15. 15.534 − 498 =
16. 16.891 − 427 =
17. 17.980 − 658 =
18. 18.776 − 697 =
19. 19.853 − 508 =
20. 20.845 − 797 =
21. 21.595 − 198 =
22. 22.964 − 538 =
23. 23.918 − 698 =
24. 24.863 − 699 =
25. 25.671 − 517 =
26. 26.782 − 697 =
27. 27.998 − 698 =
28. 28.638 − 597 =
29. 29.700 − 597 =
30. 30.907 − 317 =
31. 31.368 − 269 =
32. 32.914 − 797 =
33. 33.491 − 229 =
34. 34.841 − 159 =
35. 35.920 − 397 =
36. 36.937 − 687 =
37. 37.695 − 458 =
38. 38.754 − 699 =
39. 39.445 − 419 =
40. 40.877 − 329 =

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