Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 868 · 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. 1.634 − 297 =
2. 2.367 − 198 =
3. 3.420 − 397 =
4. 4.649 − 578 =
5. 5.947 − 397 =
6. 6.922 − 168 =
7. 7.867 − 498 =
8. 8.648 − 397 =
9. 9.247 − 218 =
10. 10.979 − 499 =
11. 11.665 − 297 =
12. 12.643 − 398 =
13. 13.959 − 399 =
14. 14.578 − 539 =
15. 15.398 − 249 =
16. 16.889 − 208 =
17. 17.722 − 349 =
18. 18.719 − 597 =
19. 19.660 − 489 =
20. 20.856 − 247 =
21. 21.891 − 369 =
22. 22.569 − 509 =
23. 23.850 − 128 =
24. 24.883 − 397 =
25. 25.697 − 399 =
26. 26.289 − 168 =
27. 27.782 − 698 =
28. 28.708 − 579 =
29. 29.566 − 437 =
30. 30.820 − 499 =
31. 31.881 − 179 =
32. 32.846 − 397 =
33. 33.682 − 439 =
34. 34.670 − 298 =
35. 35.987 − 798 =
36. 36.723 − 358 =
37. 37.900 − 198 =
38. 38.989 − 498 =
39. 39.602 − 217 =
40. 40.773 − 497 =

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