Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 723 · 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. 1.748 − 699 =
2. 2.536 − 177 =
3. 3.960 − 697 =
4. 4.882 − 269 =
5. 5.815 − 498 =
6. 6.676 − 617 =
7. 7.959 − 688 =
8. 8.936 − 799 =
9. 9.504 − 249 =
10. 10.324 − 168 =
11. 11.599 − 319 =
12. 12.508 − 309 =
13. 13.649 − 397 =
14. 14.817 − 797 =
15. 15.296 − 279 =
16. 16.995 − 517 =
17. 17.601 − 438 =
18. 18.716 − 357 =
19. 19.577 − 498 =
20. 20.471 − 298 =
21. 21.837 − 698 =
22. 22.851 − 199 =
23. 23.716 − 698 =
24. 24.997 − 797 =
25. 25.639 − 497 =
26. 26.952 − 558 =
27. 27.330 − 308 =
28. 28.572 − 517 =
29. 29.966 − 697 =
30. 30.844 − 398 =
31. 31.623 − 599 =
32. 32.971 − 318 =
33. 33.958 − 399 =
34. 34.869 − 298 =
35. 35.507 − 299 =
36. 36.820 − 197 =
37. 37.506 − 398 =
38. 38.319 − 199 =
39. 39.816 − 699 =
40. 40.930 − 198 =

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