Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 500 · 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. 1.710 − 209 =
2. 2.983 − 299 =
3. 3.906 − 799 =
4. 4.292 − 177 =
5. 5.567 − 499 =
6. 6.637 − 297 =
7. 7.755 − 469 =
8. 8.584 − 349 =
9. 9.497 − 197 =
10. 10.430 − 397 =
11. 11.870 − 417 =
12. 12.874 − 507 =
13. 13.371 − 119 =
14. 14.513 − 399 =
15. 15.726 − 497 =
16. 16.848 − 579 =
17. 17.553 − 199 =
18. 18.773 − 699 =
19. 19.841 − 399 =
20. 20.614 − 598 =
21. 21.314 − 298 =
22. 22.958 − 369 =
23. 23.888 − 698 =
24. 24.471 − 429 =
25. 25.795 − 597 =
26. 26.431 − 399 =
27. 27.237 − 199 =
28. 28.863 − 648 =
29. 29.596 − 479 =
30. 30.574 − 499 =
31. 31.707 − 657 =
32. 32.829 − 297 =
33. 33.870 − 598 =
34. 34.593 − 308 =
35. 35.922 − 439 =
36. 36.865 − 697 =
37. 37.931 − 497 =
38. 38.335 − 297 =
39. 39.491 − 299 =
40. 40.970 − 397 =

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