Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 740 · 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. 1.403 − 199 =
2. 2.734 − 287 =
3. 3.919 − 698 =
4. 4.665 − 238 =
5. 5.901 − 799 =
6. 6.822 − 298 =
7. 7.918 − 539 =
8. 8.518 − 419 =
9. 9.226 − 178 =
10. 10.832 − 798 =
11. 11.707 − 527 =
12. 12.968 − 798 =
13. 13.359 − 239 =
14. 14.292 − 149 =
15. 15.562 − 199 =
16. 16.850 − 289 =
17. 17.543 − 199 =
18. 18.846 − 598 =
19. 19.524 − 497 =
20. 20.909 − 299 =
21. 21.575 − 217 =
22. 22.704 − 647 =
23. 23.923 − 799 =
24. 24.612 − 498 =
25. 25.633 − 598 =
26. 26.947 − 797 =
27. 27.675 − 509 =
28. 28.829 − 597 =
29. 29.881 − 649 =
30. 30.271 − 198 =
31. 31.432 − 359 =
32. 32.547 − 198 =
33. 33.929 − 699 =
34. 34.265 − 218 =
35. 35.974 − 799 =
36. 36.736 − 548 =
37. 37.577 − 449 =
38. 38.806 − 299 =
39. 39.911 − 299 =
40. 40.860 − 489 =

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