Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 711 · 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. 1.604 − 278 =
2. 2.803 − 577 =
3. 3.737 − 468 =
4. 4.568 − 498 =
5. 5.940 − 538 =
6. 6.990 − 798 =
7. 7.189 − 157 =
8. 8.393 − 357 =
9. 9.492 − 328 =
10. 10.354 − 248 =
11. 11.856 − 568 =
12. 12.540 − 519 =
13. 13.920 − 798 =
14. 14.511 − 178 =
15. 15.883 − 689 =
16. 16.896 − 798 =
17. 17.498 − 258 =
18. 18.473 − 199 =
19. 19.453 − 397 =
20. 20.591 − 419 =
21. 21.960 − 618 =
22. 22.299 − 197 =
23. 23.389 − 197 =
24. 24.565 − 279 =
25. 25.673 − 229 =
26. 26.997 − 598 =
27. 27.622 − 497 =
28. 28.982 − 598 =
29. 29.541 − 498 =
30. 30.910 − 698 =
31. 31.842 − 798 =
32. 32.937 − 678 =
33. 33.518 − 497 =
34. 34.352 − 207 =
35. 35.227 − 147 =
36. 36.920 − 477 =
37. 37.452 − 129 =
38. 38.747 − 697 =
39. 39.513 − 498 =
40. 40.894 − 387 =

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