A software program I have generates all stock or movement in full/partial
format, so if I have 10 full cases and a case with 4 of 6 items in it, it
represents inventory as
10/4. A case of 200 might show 4/198 meaning 4 full and 198 loose. It does
the same for sales, inventory, etc.

How can I convert this into something usefull, like 10.67, or even rounded
to 11?