Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 811 · 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. 1.947 − 497 =
2. 2.924 − 627 =
3. 3.978 − 389 =
4. 4.954 − 199 =
5. 5.564 − 418 =
6. 6.476 − 319 =
7. 7.370 − 269 =
8. 8.340 − 169 =
9. 9.652 − 199 =
10. 10.756 − 599 =
11. 11.854 − 399 =
12. 12.434 − 337 =
13. 13.629 − 177 =
14. 14.710 − 659 =
15. 15.998 − 199 =
16. 16.477 − 117 =
17. 17.692 − 579 =
18. 18.621 − 369 =
19. 19.718 − 598 =
20. 20.656 − 299 =
21. 21.524 − 147 =
22. 22.869 − 397 =
23. 23.905 − 508 =
24. 24.585 − 529 =
25. 25.723 − 278 =
26. 26.309 − 149 =
27. 27.455 − 398 =
28. 28.653 − 549 =
29. 29.754 − 199 =
30. 30.479 − 279 =
31. 31.901 − 298 =
32. 32.559 − 499 =
33. 33.827 − 357 =
34. 34.961 − 397 =
35. 35.606 − 498 =
36. 36.438 − 279 =
37. 37.747 − 599 =
38. 38.485 − 399 =
39. 39.812 − 499 =
40. 40.700 − 599 =

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