Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 756 · 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. 1.774 − 698 =
2. 2.462 − 369 =
3. 3.750 − 697 =
4. 4.767 − 267 =
5. 5.380 − 298 =
6. 6.353 − 307 =
7. 7.834 − 799 =
8. 8.257 − 169 =
9. 9.915 − 469 =
10. 10.845 − 668 =
11. 11.681 − 239 =
12. 12.441 − 417 =
13. 13.546 − 419 =
14. 14.947 − 217 =
15. 15.939 − 798 =
16. 16.786 − 689 =
17. 17.831 − 697 =
18. 18.587 − 499 =
19. 19.761 − 627 =
20. 20.488 − 298 =
21. 21.858 − 497 =
22. 22.872 − 499 =
23. 23.757 − 497 =
24. 24.325 − 187 =
25. 25.846 − 397 =
26. 26.972 − 599 =
27. 27.368 − 319 =
28. 28.908 − 177 =
29. 29.440 − 297 =
30. 30.784 − 678 =
31. 31.904 − 598 =
32. 32.630 − 599 =
33. 33.571 − 399 =
34. 34.527 − 299 =
35. 35.886 − 497 =
36. 36.863 − 798 =
37. 37.997 − 599 =
38. 38.870 − 227 =
39. 39.786 − 139 =
40. 40.481 − 297 =

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