Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 520 · 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. 1.744 − 557 =
2. 2.490 − 399 =
3. 3.856 − 627 =
4. 4.947 − 799 =
5. 5.963 − 197 =
6. 6.540 − 137 =
7. 7.307 − 129 =
8. 8.948 − 698 =
9. 9.909 − 398 =
10. 10.425 − 317 =
11. 11.853 − 798 =
12. 12.771 − 499 =
13. 13.553 − 329 =
14. 14.874 − 298 =
15. 15.575 − 497 =
16. 16.945 − 499 =
17. 17.929 − 307 =
18. 18.894 − 317 =
19. 19.910 − 598 =
20. 20.902 − 699 =
21. 21.816 − 369 =
22. 22.781 − 328 =
23. 23.650 − 397 =
24. 24.678 − 477 =
25. 25.812 − 589 =
26. 26.319 − 217 =
27. 27.978 − 299 =
28. 28.488 − 198 =
29. 29.381 − 308 =
30. 30.436 − 227 =
31. 31.920 − 198 =
32. 32.748 − 599 =
33. 33.642 − 379 =
34. 34.515 − 397 =
35. 35.994 − 689 =
36. 36.717 − 379 =
37. 37.302 − 198 =
38. 38.857 − 187 =
39. 39.456 − 298 =
40. 40.901 − 698 =

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