Discount on Unit Price
with Posterita POS you can even give the discount on the unit price.

The Discount Control Screen
Posterita POS controls the discount on several level, there is a price limit on each product and it can actually be enforced that no discount is ever given below that price limit. We can also set a maximum percentage that the salesperson is allowed to give. And if you are actually the manager and can't even be bothered with these price limits due to broken products, or having to deal with very special circumstances. Then the override price limit will fit the deal.

Discount Options: Percentage or Absolute
Posterita POS discount features are numerous, here you can see that it allows the sales person to give a discount in terms of absolute value or even in terms of percentage. You just have to type in either one of them and it will automatically calculate the appropriate equivalent. And you can even do it on the total! Enough of these point of sales where you have to apply 10% on over 50 lines!
Below you can have a look at a demo of the discount functionality.