How to track yards left on a roll with a single SKU and using dual UOM?

We buy carpeting from vendors and have found the number of yards on the individual rolls is different.  How do we receive them accurately so that we know how much is left on each roll? We buy in rolls and sell in square yards, so we are using dual uom already.  We are on JDE EnterpriseOne 9.0 with TR 8.98.

Example:

SKU 123 is for beige carpet from vendor M.   Roll #1 has 208 yards off the truck, roll #2 has 204, and the 3rd has 198.  In the food industry catch weight is used, but we aren't receiving nor selling by weight.