Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 992 · 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. 1.579 − 399 =
2. 2.714 − 508 =
3. 3.313 − 249 =
4. 4.893 − 398 =
5. 5.931 − 198 =
6. 6.376 − 198 =
7. 7.527 − 497 =
8. 8.906 − 497 =
9. 9.918 − 119 =
10. 10.450 − 299 =
11. 11.962 − 569 =
12. 12.918 − 697 =
13. 13.281 − 199 =
14. 14.435 − 118 =
15. 15.772 − 309 =
16. 16.937 − 799 =
17. 17.960 − 297 =
18. 18.612 − 498 =
19. 19.973 − 198 =
20. 20.361 − 339 =
21. 21.748 − 697 =
22. 22.325 − 199 =
23. 23.867 − 697 =
24. 24.877 − 298 =
25. 25.495 − 439 =
26. 26.235 − 137 =
27. 27.820 − 378 =
28. 28.681 − 479 =
29. 29.609 − 167 =
30. 30.969 − 199 =
31. 31.392 − 239 =
32. 32.469 − 397 =
33. 33.476 − 398 =
34. 34.845 − 598 =
35. 35.230 − 197 =
36. 36.652 − 299 =
37. 37.928 − 599 =
38. 38.223 − 197 =
39. 39.950 − 329 =
40. 40.315 − 297 =

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