Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 159 · 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. 1.847 − 799 =
2. 2.410 − 378 =
3. 3.920 − 427 =
4. 4.884 − 298 =
5. 5.925 − 297 =
6. 6.863 − 419 =
7. 7.869 − 589 =
8. 8.685 − 398 =
9. 9.786 − 208 =
10. 10.780 − 599 =
11. 11.491 − 157 =
12. 12.927 − 598 =
13. 13.409 − 219 =
14. 14.274 − 179 =
15. 15.859 − 649 =
16. 16.588 − 497 =
17. 17.527 − 399 =
18. 18.780 − 679 =
19. 19.805 − 498 =
20. 20.326 − 159 =
21. 21.684 − 599 =
22. 22.518 − 497 =
23. 23.662 − 297 =
24. 24.623 − 408 =
25. 25.890 − 189 =
26. 26.519 − 499 =
27. 27.586 − 498 =
28. 28.451 − 327 =
29. 29.539 − 309 =
30. 30.558 − 499 =
31. 31.807 − 699 =
32. 32.225 − 199 =
33. 33.788 − 409 =
34. 34.625 − 387 =
35. 35.893 − 598 =
36. 36.862 − 699 =
37. 37.316 − 297 =
38. 38.716 − 218 =
39. 39.717 − 199 =
40. 40.652 − 498 =

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