Purchasing increments

I've got a question that cannot be unique [at least, I sure HOPE it's not unique!]. We buy materials to particular projects, which is common. But, when we set up purchase orders in Vantage, when the buyer enters an order for 312 screws, Vantage will process the order for, say, 3.12 PACKAGES of screws, since I've entered the required conversion to go from our inventory UM of 'each', to the vendor's selling UM of 'pack', in this case of 100.

Obviously, no one buys twelve one-hundredths of a package of screws. But this sort of rounding [which MRP will do, but we're not using MRP for some other reasons] should be easily automated. Is there some Vantage secret I've not found, or has anyone done this? If yes, would you please share?

TIA,
Lynn Thomas
SAIC