CC and IU's cannot be interchanged. This is off the top of my head but an IU is a specific dose of a specific compound that results in a specific response. 1iu of vit C could be 500mg while 1iu of potassium could be 100. Catch my drift?
You can reconstitute it however you like. I've been going at 60 units or .6ml and taking 5iu of gh per shot. So I load up .3ml and that's 5iu. You are correct with the math but the IU thing is kinda weird.