Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 882 · 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. 1.789 − 297 =
2. 2.421 − 399 =
3. 3.712 − 598 =
4. 4.688 − 339 =
5. 5.775 − 579 =
6. 6.955 − 568 =
7. 7.748 − 629 =
8. 8.898 − 348 =
9. 9.624 − 499 =
10. 10.724 − 399 =
11. 11.638 − 239 =
12. 12.639 − 299 =
13. 13.914 − 599 =
14. 14.787 − 407 =
15. 15.400 − 297 =
16. 16.604 − 397 =
17. 17.879 − 398 =
18. 18.992 − 597 =
19. 19.836 − 637 =
20. 20.839 − 399 =
21. 21.493 − 338 =
22. 22.330 − 199 =
23. 23.792 − 587 =
24. 24.506 − 399 =
25. 25.697 − 319 =
26. 26.968 − 797 =
27. 27.771 − 599 =
28. 28.862 − 308 =
29. 29.364 − 198 =
30. 30.754 − 298 =
31. 31.819 − 499 =
32. 32.937 − 649 =
33. 33.819 − 597 =
34. 34.512 − 299 =
35. 35.734 − 269 =
36. 36.711 − 248 =
37. 37.463 − 198 =
38. 38.838 − 639 =
39. 39.869 − 497 =
40. 40.351 − 199 =

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