Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 405 · 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. 1.484 − 288 =
2. 2.663 − 257 =
3. 3.723 − 549 =
4. 4.855 − 698 =
5. 5.460 − 198 =
6. 6.715 − 398 =
7. 7.755 − 557 =
8. 8.503 − 397 =
9. 9.725 − 198 =
10. 10.749 − 399 =
11. 11.240 − 159 =
12. 12.555 − 327 =
13. 13.797 − 597 =
14. 14.452 − 389 =
15. 15.901 − 647 =
16. 16.799 − 499 =
17. 17.537 − 339 =
18. 18.391 − 359 =
19. 19.235 − 217 =
20. 20.935 − 408 =
21. 21.533 − 199 =
22. 22.662 − 597 =
23. 23.686 − 498 =
24. 24.883 − 799 =
25. 25.901 − 267 =
26. 26.612 − 549 =
27. 27.655 − 299 =
28. 28.919 − 518 =
29. 29.658 − 398 =
30. 30.859 − 799 =
31. 31.824 − 118 =
32. 32.629 − 307 =
33. 33.899 − 497 =
34. 34.556 − 298 =
35. 35.389 − 258 =
36. 36.476 − 187 =
37. 37.882 − 799 =
38. 38.541 − 497 =
39. 39.852 − 799 =
40. 40.865 − 799 =

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