Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 346 · 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. 1.747 − 697 =
2. 2.692 − 638 =
3. 3.762 − 649 =
4. 4.959 − 407 =
5. 5.972 − 328 =
6. 6.670 − 599 =
7. 7.610 − 377 =
8. 8.684 − 399 =
9. 9.991 − 607 =
10. 10.645 − 199 =
11. 11.874 − 179 =
12. 12.775 − 477 =
13. 13.979 − 197 =
14. 14.915 − 799 =
15. 15.647 − 598 =
16. 16.446 − 199 =
17. 17.847 − 498 =
18. 18.613 − 268 =
19. 19.890 − 699 =
20. 20.446 − 198 =
21. 21.915 − 198 =
22. 22.700 − 239 =
23. 23.802 − 699 =
24. 24.715 − 247 =
25. 25.961 − 458 =
26. 26.423 − 197 =
27. 27.638 − 569 =
28. 28.686 − 298 =
29. 29.942 − 499 =
30. 30.755 − 197 =
31. 31.794 − 497 =
32. 32.593 − 469 =
33. 33.976 − 539 =
34. 34.360 − 127 =
35. 35.869 − 697 =
36. 36.957 − 798 =
37. 37.249 − 209 =
38. 38.293 − 159 =
39. 39.726 − 197 =
40. 40.403 − 128 =

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