Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 473 · 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. 1.974 − 799 =
2. 2.736 − 597 =
3. 3.366 − 197 =
4. 4.717 − 357 =
5. 5.414 − 378 =
6. 6.969 − 647 =
7. 7.793 − 599 =
8. 8.771 − 398 =
9. 9.670 − 439 =
10. 10.737 − 698 =
11. 11.636 − 599 =
12. 12.979 − 199 =
13. 13.733 − 487 =
14. 14.594 − 409 =
15. 15.414 − 399 =
16. 16.530 − 497 =
17. 17.849 − 797 =
18. 18.849 − 538 =
19. 19.571 − 408 =
20. 20.834 − 669 =
21. 21.747 − 257 =
22. 22.432 − 299 =
23. 23.453 − 227 =
24. 24.953 − 399 =
25. 25.914 − 699 =
26. 26.816 − 398 =
27. 27.737 − 198 =
28. 28.973 − 598 =
29. 29.517 − 459 =
30. 30.437 − 369 =
31. 31.442 − 137 =
32. 32.920 − 368 =
33. 33.720 − 599 =
34. 34.384 − 358 =
35. 35.676 − 457 =
36. 36.785 − 588 =
37. 37.290 − 227 =
38. 38.217 − 198 =
39. 39.752 − 699 =
40. 40.432 − 357 =

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