Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 794 · 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. 1.937 − 199 =
2. 2.594 − 199 =
3. 3.575 − 298 =
4. 4.830 − 468 =
5. 5.858 − 699 =
6. 6.825 − 298 =
7. 7.314 − 297 =
8. 8.850 − 497 =
9. 9.442 − 428 =
10. 10.865 − 509 =
11. 11.400 − 268 =
12. 12.526 − 299 =
13. 13.730 − 687 =
14. 14.950 − 597 =
15. 15.385 − 197 =
16. 16.983 − 699 =
17. 17.813 − 297 =
18. 18.664 − 217 =
19. 19.700 − 498 =
20. 20.640 − 398 =
21. 21.923 − 647 =
22. 22.284 − 127 =
23. 23.813 − 168 =
24. 24.725 − 659 =
25. 25.516 − 489 =
26. 26.708 − 598 =
27. 27.898 − 628 =
28. 28.792 − 508 =
29. 29.923 − 498 =
30. 30.995 − 689 =
31. 31.785 − 699 =
32. 32.704 − 199 =
33. 33.839 − 799 =
34. 34.869 − 168 =
35. 35.947 − 697 =
36. 36.959 − 498 =
37. 37.907 − 248 =
38. 38.811 − 629 =
39. 39.466 − 399 =
40. 40.977 − 667 =

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