Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 181 · 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. 1.748 − 198 =
2. 2.856 − 699 =
3. 3.647 − 198 =
4. 4.378 − 199 =
5. 5.914 − 799 =
6. 6.994 − 398 =
7. 7.787 − 499 =
8. 8.553 − 227 =
9. 9.523 − 368 =
10. 10.944 − 799 =
11. 11.746 − 618 =
12. 12.371 − 197 =
13. 13.969 − 298 =
14. 14.749 − 397 =
15. 15.554 − 378 =
16. 16.824 − 607 =
17. 17.847 − 799 =
18. 18.846 − 598 =
19. 19.856 − 229 =
20. 20.186 − 169 =
21. 21.867 − 517 =
22. 22.936 − 267 =
23. 23.424 − 118 =
24. 24.635 − 409 =
25. 25.779 − 377 =
26. 26.541 − 257 =
27. 27.566 − 198 =
28. 28.695 − 528 =
29. 29.440 − 147 =
30. 30.770 − 699 =
31. 31.456 − 397 =
32. 32.896 − 187 =
33. 33.836 − 798 =
34. 34.693 − 208 =
35. 35.971 − 528 =
36. 36.827 − 399 =
37. 37.765 − 497 =
38. 38.696 − 228 =
39. 39.877 − 339 =
40. 40.406 − 358 =

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