Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 914 · 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. 1.817 − 397 =
2. 2.401 − 298 =
3. 3.712 − 698 =
4. 4.688 − 609 =
5. 5.958 − 399 =
6. 6.790 − 659 =
7. 7.955 − 497 =
8. 8.923 − 487 =
9. 9.925 − 198 =
10. 10.453 − 227 =
11. 11.749 − 587 =
12. 12.712 − 198 =
13. 13.461 − 367 =
14. 14.326 − 199 =
15. 15.946 − 697 =
16. 16.775 − 699 =
17. 17.644 − 229 =
18. 18.533 − 298 =
19. 19.914 − 697 =
20. 20.655 − 277 =
21. 21.458 − 278 =
22. 22.562 − 457 =
23. 23.993 − 118 =
24. 24.467 − 249 =
25. 25.233 − 197 =
26. 26.743 − 287 =
27. 27.276 − 198 =
28. 28.903 − 499 =
29. 29.868 − 497 =
30. 30.882 − 408 =
31. 31.466 − 268 =
32. 32.249 − 217 =
33. 33.662 − 247 =
34. 34.525 − 407 =
35. 35.704 − 487 =
36. 36.545 − 199 =
37. 37.924 − 649 =
38. 38.523 − 399 =
39. 39.819 − 597 =
40. 40.628 − 477 =

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