Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 411 · 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. 1.987 − 429 =
2. 2.398 − 297 =
3. 3.372 − 207 =
4. 4.884 − 497 =
5. 5.997 − 398 =
6. 6.895 − 598 =
7. 7.561 − 299 =
8. 8.863 − 598 =
9. 9.635 − 399 =
10. 10.966 − 559 =
11. 11.842 − 698 =
12. 12.358 − 159 =
13. 13.692 − 399 =
14. 14.420 − 399 =
15. 15.338 − 298 =
16. 16.675 − 497 =
17. 17.938 − 599 =
18. 18.642 − 597 =
19. 19.870 − 597 =
20. 20.959 − 298 =
21. 21.793 − 629 =
22. 22.520 − 399 =
23. 23.729 − 599 =
24. 24.723 − 257 =
25. 25.836 − 387 =
26. 26.474 − 209 =
27. 27.753 − 199 =
28. 28.349 − 139 =
29. 29.800 − 698 =
30. 30.727 − 597 =
31. 31.429 − 397 =
32. 32.975 − 599 =
33. 33.517 − 497 =
34. 34.674 − 197 =
35. 35.522 − 347 =
36. 36.247 − 197 =
37. 37.919 − 509 =
38. 38.743 − 598 =
39. 39.413 − 148 =
40. 40.888 − 667 =

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