Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 925 · 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. 1.890 − 698 =
2. 2.564 − 429 =
3. 3.792 − 497 =
4. 4.819 − 299 =
5. 5.223 − 197 =
6. 6.463 − 358 =
7. 7.319 − 199 =
8. 8.540 − 469 =
9. 9.474 − 288 =
10. 10.886 − 198 =
11. 11.545 − 407 =
12. 12.598 − 499 =
13. 13.865 − 199 =
14. 14.936 − 659 =
15. 15.952 − 498 =
16. 16.501 − 398 =
17. 17.790 − 697 =
18. 18.237 − 197 =
19. 19.553 − 249 =
20. 20.768 − 118 =
21. 21.576 − 257 =
22. 22.569 − 157 =
23. 23.372 − 149 =
24. 24.718 − 198 =
25. 25.813 − 299 =
26. 26.854 − 389 =
27. 27.584 − 499 =
28. 28.490 − 198 =
29. 29.731 − 699 =
30. 30.709 − 198 =
31. 31.961 − 479 =
32. 32.764 − 697 =
33. 33.879 − 347 =
34. 34.648 − 399 =
35. 35.229 − 129 =
36. 36.974 − 248 =
37. 37.768 − 497 =
38. 38.305 − 189 =
39. 39.664 − 399 =
40. 40.376 − 197 =

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