This method is pretty straight-forward and very easy to use and implement in a low volume high cost per item retail format. COGS = Beginning Inventory + Purchases - Ending Inventory. Gross Margin. This is simply the difference between what an item cost and the price for which it sells. For example, if Store A and B have the same sales, yet Store A's gross margin is 50 percent and Store B's gross margin is 55 percent, it's easy to see which store is faring better.
Supertype is an entity type that has got relationship (parent to child relationship) with one or more subtypes and it contains attributes that are common to its subtypes. Subtypes are subgroups of the supertype entity and have unique attributes, but they will be different from each subtype. Supertypes and Subtypes are parent and child entities respectively and the primary keys of supertype and subtype are always identical. E.g.
24.2 Character entity references for ISO 8859-1 characters. The character entity references in this section produce characters whose numeric equivalents should already be supported by conforming HTML 2.0 user agents. Thus, the character entity reference &divide; is a more convenient form than &#247; for obtaining the division sign (Ã·).