We sell eggs at farmers markets by the dozen. We use our own cartons, and customers will bring them back to us for a discount. When I setup a discount, it's not really working the way I think of discounts (or maybe I'm using the wrong term for what I'm trying to do)

Basically a customer brings back an egg carton, and wants to buy another dozen eggs. The discount works fine, in this scenario. I tap 1 doz eggs, then tap the carton return discount. The math works out perfect.

But, when I have a customer bring in say, 2 cartons, and wants to buy 3 dozen eggs. I tab 1 doz eggs (3 times), then I can only apply the carton discount once, because it's greyed out after the 1'st tap. I can't give them a discount for 2 returned cartons.

For now, I just have a variable discount, so I manually have to type in the amount - which is fine, but you know, I'd like to take as much thinking out of it as I can 😉