Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 235 · 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. 1.737 − 298 =
2. 2.645 − 499 =
3. 3.820 − 199 =
4. 4.341 − 319 =
5. 5.915 − 609 =
6. 6.462 − 299 =
7. 7.848 − 598 =
8. 8.281 − 158 =
9. 9.653 − 458 =
10. 10.705 − 299 =
11. 11.614 − 389 =
12. 12.468 − 389 =
13. 13.581 − 198 =
14. 14.897 − 458 =
15. 15.669 − 597 =
16. 16.174 − 148 =
17. 17.482 − 197 =
18. 18.742 − 497 =
19. 19.572 − 499 =
20. 20.996 − 347 =
21. 21.342 − 227 =
22. 22.716 − 639 =
23. 23.755 − 198 =
24. 24.904 − 599 =
25. 25.847 − 497 =
26. 26.695 − 617 =
27. 27.845 − 498 =
28. 28.790 − 399 =
29. 29.963 − 387 =
30. 30.848 − 658 =
31. 31.551 − 387 =
32. 32.678 − 499 =
33. 33.441 − 197 =
34. 34.475 − 299 =
35. 35.982 − 169 =
36. 36.186 − 159 =
37. 37.995 − 247 =
38. 38.467 − 198 =
39. 39.427 − 299 =
40. 40.850 − 468 =

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