Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 945 · 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. 1.929 − 699 =
2. 2.560 − 498 =
3. 3.936 − 267 =
4. 4.616 − 599 =
5. 5.657 − 199 =
6. 6.944 − 618 =
7. 7.467 − 269 =
8. 8.929 − 267 =
9. 9.636 − 298 =
10. 10.499 − 297 =
11. 11.667 − 228 =
12. 12.822 − 249 =
13. 13.764 − 598 =
14. 14.392 − 257 =
15. 15.915 − 797 =
16. 16.515 − 129 =
17. 17.334 − 297 =
18. 18.982 − 619 =
19. 19.836 − 659 =
20. 20.924 − 299 =
21. 21.665 − 609 =
22. 22.836 − 418 =
23. 23.949 − 699 =
24. 24.854 − 799 =
25. 25.370 − 208 =
26. 26.928 − 797 =
27. 27.690 − 599 =
28. 28.526 − 497 =
29. 29.816 − 797 =
30. 30.670 − 377 =
31. 31.990 − 197 =
32. 32.739 − 668 =
33. 33.734 − 697 =
34. 34.899 − 799 =
35. 35.666 − 499 =
36. 36.235 − 199 =
37. 37.729 − 648 =
38. 38.902 − 288 =
39. 39.271 − 237 =
40. 40.836 − 697 =

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