Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 125 · 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. 1.594 − 437 =
2. 2.343 − 198 =
3. 3.790 − 497 =
4. 4.242 − 129 =
5. 5.888 − 498 =
6. 6.916 − 599 =
7. 7.641 − 599 =
8. 8.969 − 799 =
9. 9.828 − 427 =
10. 10.858 − 599 =
11. 11.773 − 197 =
12. 12.760 − 489 =
13. 13.745 − 499 =
14. 14.362 − 229 =
15. 15.826 − 699 =
16. 16.619 − 147 =
17. 17.538 − 269 =
18. 18.430 − 199 =
19. 19.342 − 199 =
20. 20.325 − 259 =
21. 21.891 − 699 =
22. 22.665 − 599 =
23. 23.518 − 498 =
24. 24.619 − 489 =
25. 25.987 − 799 =
26. 26.918 − 797 =
27. 27.573 − 397 =
28. 28.901 − 519 =
29. 29.608 − 198 =
30. 30.600 − 499 =
31. 31.356 − 197 =
32. 32.408 − 349 =
33. 33.441 − 379 =
34. 34.676 − 598 =
35. 35.488 − 239 =
36. 36.603 − 568 =
37. 37.355 − 299 =
38. 38.960 − 799 =
39. 39.851 − 639 =
40. 40.833 − 119 =

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