Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 275 · 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. 1.342 − 297 =
2. 2.763 − 699 =
3. 3.867 − 798 =
4. 4.763 − 698 =
5. 5.846 − 799 =
6. 6.924 − 598 =
7. 7.874 − 698 =
8. 8.902 − 499 =
9. 9.961 − 197 =
10. 10.792 − 167 =
11. 11.696 − 298 =
12. 12.901 − 399 =
13. 13.464 − 297 =
14. 14.777 − 197 =
15. 15.780 − 198 =
16. 16.955 − 499 =
17. 17.755 − 637 =
18. 18.745 − 699 =
19. 19.939 − 597 =
20. 20.436 − 399 =
21. 21.367 − 199 =
22. 22.868 − 488 =
23. 23.899 − 439 =
24. 24.987 − 797 =
25. 25.794 − 497 =
26. 26.673 − 197 =
27. 27.397 − 299 =
28. 28.701 − 598 =
29. 29.994 − 597 =
30. 30.628 − 399 =
31. 31.681 − 637 =
32. 32.472 − 289 =
33. 33.841 − 149 =
34. 34.973 − 698 =
35. 35.809 − 198 =
36. 36.860 − 598 =
37. 37.821 − 599 =
38. 38.993 − 298 =
39. 39.765 − 299 =
40. 40.684 − 638 =

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