If you would like to calculate 4 * 1 1/5, you can do this using the following steps:
1 1/5 = 6/5
4 * 1 1/5 = 4 * 6/5 = 24/5 = 4 4/5
The correct result would be 4 4/5.
If that was not your question, please ask differently and I will try and answer your question. :)