Assuming that the number you are attempting to write is 5 8/5, you're whole number would be 6 3/5.
However, if the number is actually 58/5, then the whole number would be 11 3/5.
Here's how to find the answer:
For 5 8/5, you must find how many times 5 goes into the numerator since 5/5 is one whole number. However, there will sometimes be remainders as presented in this question, thus leaving you with another fraction which is 3/5.
Hope this helps!