When you connect the Donation Tiers campaign, the widget will display like this on your website's product pages (you can also use Manual mode to show the widget at cart level):

Once a donation is added, expect the widget to transform and indicate a donation has been added to cart, like so:

Once in cart, if you have added our code to hide increments in the cart, the Donation Tiers donation product will appear like so:

If you haven't hidden the increments, you will see data appear in the Price and Quantity columns. 

Important note: 

If your customer has chosen one of your preset donation amounts, the quantity will be "1" regardless of the donation amount. 

However, if your customer has input a custom donation amount, the quantity will be counted in cents ($0.01 = 1 unit) -- for example, if your customer has input $2, the quantity units will be 200.