Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 452 · 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. 1.570 − 198 =
2. 2.687 − 648 =
3. 3.794 − 587 =
4. 4.933 − 498 =
5. 5.870 − 399 =
6. 6.850 − 497 =
7. 7.460 − 237 =
8. 8.592 − 547 =
9. 9.935 − 697 =
10. 10.774 − 617 =
11. 11.871 − 797 =
12. 12.751 − 617 =
13. 13.827 − 297 =
14. 14.936 − 797 =
15. 15.753 − 599 =
16. 16.888 − 338 =
17. 17.764 − 298 =
18. 18.936 − 219 =
19. 19.531 − 239 =
20. 20.655 − 629 =
21. 21.987 − 257 =
22. 22.878 − 598 =
23. 23.691 − 218 =
24. 24.782 − 497 =
25. 25.530 − 197 =
26. 26.854 − 399 =
27. 27.697 − 497 =
28. 28.428 − 197 =
29. 29.372 − 228 =
30. 30.288 − 197 =
31. 31.801 − 598 =
32. 32.891 − 698 =
33. 33.711 − 349 =
34. 34.653 − 399 =
35. 35.938 − 618 =
36. 36.893 − 119 =
37. 37.621 − 179 =
38. 38.846 − 698 =
39. 39.436 − 299 =
40. 40.825 − 798 =

Free mental maths lessons, practice and worksheets at talentjr.in/mental-maths