In a design problem, your calculation is instead, "given an operating current and conditions of use, what wire size should be used?". This is the inverse problem of what the NEC directly prescribes, and therefore when you rearrange it with algebra, you get division instead of multiplication.

I think that is the answer I was looking for. Thanks for the help. I have been studying without having a instructor and some of my coworkers are not to knowledgeable on the test.