Is it possible to discount 1 item when multiples are purchased?

kellyferg16

Scenario: customer purchases 3 of the exact same item and hands over a coupon for x% off one item.

We found that the discount was applied to all 3 items and not just one (took some creative thinking to correctly charge the customer).

This is not an unusual practice so I have to assume we've set something up incorrectly. Any thoughts?