Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 516 · 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. 1.604 − 297 =
2. 2.370 − 158 =
3. 3.353 − 219 =
4. 4.853 − 797 =
5. 5.597 − 479 =
6. 6.383 − 299 =
7. 7.816 − 667 =
8. 8.695 − 608 =
9. 9.280 − 169 =
10. 10.833 − 298 =
11. 11.372 − 297 =
12. 12.524 − 297 =
13. 13.460 − 439 =
14. 14.929 − 528 =
15. 15.312 − 169 =
16. 16.776 − 659 =
17. 17.717 − 198 =
18. 18.427 − 199 =
19. 19.722 − 697 =
20. 20.898 − 498 =
21. 21.975 − 499 =
22. 22.846 − 798 =
23. 23.761 − 697 =
24. 24.467 − 299 =
25. 25.595 − 339 =
26. 26.608 − 398 =
27. 27.900 − 699 =
28. 28.663 − 497 =
29. 29.870 − 539 =
30. 30.851 − 497 =
31. 31.632 − 467 =
32. 32.924 − 398 =
33. 33.489 − 297 =
34. 34.895 − 198 =
35. 35.971 − 699 =
36. 36.863 − 698 =
37. 37.718 − 598 =
38. 38.477 − 397 =
39. 39.584 − 528 =
40. 40.362 − 318 =

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