Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 168 · 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. 1.711 − 489 =
2. 2.946 − 398 =
3. 3.904 − 338 =
4. 4.607 − 497 =
5. 5.222 − 168 =
6. 6.913 − 799 =
7. 7.990 − 637 =
8. 8.911 − 467 =
9. 9.762 − 169 =
10. 10.851 − 659 =
11. 11.700 − 597 =
12. 12.513 − 288 =
13. 13.737 − 199 =
14. 14.653 − 397 =
15. 15.495 − 367 =
16. 16.758 − 698 =
17. 17.846 − 208 =
18. 18.846 − 798 =
19. 19.623 − 548 =
20. 20.904 − 287 =
21. 21.852 − 699 =
22. 22.185 − 158 =
23. 23.324 − 297 =
24. 24.423 − 398 =
25. 25.982 − 799 =
26. 26.765 − 677 =
27. 27.424 − 198 =
28. 28.642 − 497 =
29. 29.726 − 399 =
30. 30.553 − 197 =
31. 31.899 − 297 =
32. 32.781 − 199 =
33. 33.480 − 397 =
34. 34.804 − 397 =
35. 35.429 − 199 =
36. 36.615 − 397 =
37. 37.615 − 199 =
38. 38.733 − 697 =
39. 39.407 − 218 =
40. 40.695 − 677 =

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