Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 110 · 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. 1.837 − 597 =
2. 2.655 − 379 =
3. 3.896 − 598 =
4. 4.957 − 647 =
5. 5.859 − 797 =
6. 6.833 − 409 =
7. 7.943 − 498 =
8. 8.586 − 297 =
9. 9.567 − 398 =
10. 10.827 − 168 =
11. 11.546 − 509 =
12. 12.260 − 198 =
13. 13.833 − 208 =
14. 14.515 − 497 =
15. 15.759 − 608 =
16. 16.710 − 498 =
17. 17.884 − 397 =
18. 18.846 − 499 =
19. 19.409 − 357 =
20. 20.758 − 419 =
21. 21.906 − 699 =
22. 22.729 − 587 =
23. 23.702 − 469 =
24. 24.575 − 397 =
25. 25.653 − 298 =
26. 26.799 − 498 =
27. 27.931 − 289 =
28. 28.780 − 397 =
29. 29.961 − 228 =
30. 30.683 − 399 =
31. 31.449 − 288 =
32. 32.930 − 697 =
33. 33.892 − 477 =
34. 34.998 − 797 =
35. 35.973 − 599 =
36. 36.747 − 217 =
37. 37.821 − 329 =
38. 38.594 − 218 =
39. 39.413 − 128 =
40. 40.910 − 498 =

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