There are several different types of discounts that the calculator can compute for you.
1. Percentage discount: how much you can save on one item with a discount
2. Fixed amount off: enter the amount of the original price and the discount dollar value to find the new price and the amount you will save on an item
3. 2 for 1 discount: If the items are of a different amount, the cheapest item would be free, so enter the price for both items to find the amount you will pay in the transaction