Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 482 · 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. 1.840 − 297 =
2. 2.855 − 798 =
3. 3.363 − 157 =
4. 4.550 − 137 =
5. 5.711 − 379 =
6. 6.653 − 319 =
7. 7.278 − 197 =
8. 8.799 − 497 =
9. 9.763 − 367 =
10. 10.973 − 477 =
11. 11.631 − 489 =
12. 12.596 − 129 =
13. 13.859 − 268 =
14. 14.770 − 698 =
15. 15.474 − 288 =
16. 16.758 − 577 =
17. 17.903 − 589 =
18. 18.876 − 459 =
19. 19.714 − 299 =
20. 20.593 − 498 =
21. 21.560 − 408 =
22. 22.895 − 298 =
23. 23.755 − 557 =
24. 24.983 − 597 =
25. 25.748 − 669 =
26. 26.944 − 259 =
27. 27.516 − 399 =
28. 28.900 − 698 =
29. 29.773 − 199 =
30. 30.709 − 189 =
31. 31.592 − 247 =
32. 32.997 − 799 =
33. 33.883 − 467 =
34. 34.961 − 797 =
35. 35.469 − 399 =
36. 36.764 − 199 =
37. 37.826 − 198 =
38. 38.213 − 198 =
39. 39.719 − 667 =
40. 40.780 − 599 =

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