Discount 100%

[ChristerE]

We need to use a system for a specific type of registered user that allows 100% discount on selected products but when I create a new rule in Taxes & Calculation Rules and add math operation -100% the discount isn't shown, it works as supposed to up to 99.9500. The problem is the last 0.05%. If the customer orders e.g. 1000 pieces at the price of 24 kr, the discount is 23.990 kr and the cost for the customer is 10 kr when it should have been 0 kr.

Any suggestions, anyone?