Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 385 · 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. 1.759 − 597 =
2. 2.400 − 347 =
3. 3.988 − 797 =
4. 4.853 − 697 =
5. 5.888 − 399 =
6. 6.947 − 698 =
7. 7.818 − 698 =
8. 8.285 − 197 =
9. 9.543 − 498 =
10. 10.845 − 598 =
11. 11.875 − 799 =
12. 12.550 − 458 =
13. 13.642 − 598 =
14. 14.640 − 238 =
15. 15.783 − 299 =
16. 16.935 − 598 =
17. 17.687 − 299 =
18. 18.721 − 269 =
19. 19.861 − 797 =
20. 20.799 − 599 =
21. 21.926 − 798 =
22. 22.968 − 587 =
23. 23.789 − 199 =
24. 24.827 − 798 =
25. 25.782 − 529 =
26. 26.912 − 198 =
27. 27.252 − 198 =
28. 28.959 − 639 =
29. 29.712 − 458 =
30. 30.790 − 699 =
31. 31.455 − 398 =
32. 32.722 − 699 =
33. 33.812 − 448 =
34. 34.673 − 167 =
35. 35.574 − 479 =
36. 36.545 − 399 =
37. 37.773 − 117 =
38. 38.796 − 257 =
39. 39.850 − 418 =
40. 40.541 − 379 =

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