Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 216 · 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. 1.826 − 209 =
2. 2.648 − 317 =
3. 3.943 − 699 =
4. 4.858 − 649 =
5. 5.685 − 198 =
6. 6.887 − 419 =
7. 7.351 − 298 =
8. 8.876 − 298 =
9. 9.336 − 297 =
10. 10.323 − 158 =
11. 11.987 − 117 =
12. 12.920 − 797 =
13. 13.892 − 378 =
14. 14.642 − 269 =
15. 15.394 − 299 =
16. 16.578 − 168 =
17. 17.909 − 297 =
18. 18.988 − 397 =
19. 19.425 − 379 =
20. 20.979 − 798 =
21. 21.922 − 799 =
22. 22.752 − 519 =
23. 23.888 − 697 =
24. 24.731 − 149 =
25. 25.519 − 199 =
26. 26.417 − 298 =
27. 27.470 − 119 =
28. 28.711 − 597 =
29. 29.796 − 689 =
30. 30.526 − 399 =
31. 31.916 − 798 =
32. 32.765 − 268 =
33. 33.575 − 299 =
34. 34.600 − 397 =
35. 35.846 − 697 =
36. 36.840 − 498 =
37. 37.927 − 799 =
38. 38.609 − 147 =
39. 39.956 − 588 =
40. 40.983 − 678 =

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