I have product A. I sell product A as a whole, but I can also split up product A and sell it in multiple sub units of product A. I have 1 unit of product A. I have an order for a sub-unit of Product A for 1. I established that 1 sub unit of Product A equals 0.5 of Product A. Therefore, when I sell a sub-unit, my inventory for product A reduces by 0.5. In order words, 1 sub-unit = 0.5 of product A.