Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 427 · 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. 1.417 − 197 =
2. 2.889 − 329 =
3. 3.976 − 797 =
4. 4.986 − 198 =
5. 5.599 − 339 =
6. 6.837 − 697 =
7. 7.616 − 598 =
8. 8.862 − 617 =
9. 9.666 − 609 =
10. 10.663 − 579 =
11. 11.992 − 217 =
12. 12.938 − 398 =
13. 13.919 − 199 =
14. 14.707 − 497 =
15. 15.361 − 299 =
16. 16.779 − 157 =
17. 17.525 − 398 =
18. 18.887 − 697 =
19. 19.750 − 238 =
20. 20.358 − 138 =
21. 21.577 − 268 =
22. 22.962 − 799 =
23. 23.817 − 698 =
24. 24.838 − 397 =
25. 25.954 − 199 =
26. 26.480 − 217 =
27. 27.839 − 287 =
28. 28.840 − 298 =
29. 29.481 − 297 =
30. 30.723 − 699 =
31. 31.919 − 599 =
32. 32.666 − 298 =
33. 33.500 − 279 =
34. 34.862 − 797 =
35. 35.521 − 328 =
36. 36.502 − 288 =
37. 37.733 − 497 =
38. 38.775 − 499 =
39. 39.863 − 399 =
40. 40.752 − 247 =

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