Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 715 · 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. 1.718 − 198 =
2. 2.529 − 298 =
3. 3.704 − 549 =
4. 4.524 − 399 =
5. 5.997 − 198 =
6. 6.918 − 699 =
7. 7.608 − 168 =
8. 8.405 − 198 =
9. 9.666 − 198 =
10. 10.868 − 567 =
11. 11.879 − 399 =
12. 12.626 − 249 =
13. 13.868 − 797 =
14. 14.859 − 689 =
15. 15.342 − 259 =
16. 16.323 − 127 =
17. 17.732 − 197 =
18. 18.920 − 428 =
19. 19.346 − 238 =
20. 20.395 − 199 =
21. 21.524 − 397 =
22. 22.943 − 258 =
23. 23.663 − 298 =
24. 24.826 − 597 =
25. 25.585 − 468 =
26. 26.695 − 599 =
27. 27.465 − 297 =
28. 28.690 − 499 =
29. 29.688 − 307 =
30. 30.499 − 199 =
31. 31.995 − 669 =
32. 32.553 − 198 =
33. 33.593 − 398 =
34. 34.806 − 587 =
35. 35.503 − 419 =
36. 36.996 − 608 =
37. 37.424 − 397 =
38. 38.148 − 128 =
39. 39.738 − 657 =
40. 40.805 − 699 =

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