Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 556 · 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. 1.469 − 219 =
2. 2.579 − 397 =
3. 3.578 − 237 =
4. 4.630 − 299 =
5. 5.593 − 129 =
6. 6.871 − 198 =
7. 7.725 − 489 =
8. 8.496 − 438 =
9. 9.805 − 389 =
10. 10.429 − 198 =
11. 11.734 − 649 =
12. 12.836 − 697 =
13. 13.663 − 497 =
14. 14.804 − 697 =
15. 15.596 − 449 =
16. 16.655 − 389 =
17. 17.897 − 539 =
18. 18.818 − 398 =
19. 19.657 − 397 =
20. 20.562 − 287 =
21. 21.889 − 799 =
22. 22.734 − 118 =
23. 23.286 − 198 =
24. 24.563 − 297 =
25. 25.818 − 797 =
26. 26.887 − 799 =
27. 27.590 − 297 =
28. 28.650 − 398 =
29. 29.561 − 179 =
30. 30.913 − 459 =
31. 31.793 − 538 =
32. 32.761 − 399 =
33. 33.896 − 589 =
34. 34.895 − 299 =
35. 35.806 − 297 =
36. 36.964 − 329 =
37. 37.594 − 488 =
38. 38.752 − 369 =
39. 39.354 − 299 =
40. 40.759 − 158 =

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