Strange total dollar amounts in report

[Putters Adventure Golf]

When I look at my sales, they are showing different dollar amounts to what the actual values should be.  The attached shows one example of which, our item is $2, we sold 120x of these which shows correctly @ $240 in the top 5 sellers, but then in the list it is showing as $224.83?

 

[Ioakim Mukum]

The Top 5 items show you the Gross Sales.
There is the difference between Gross Sales and Net Sales.

Net Sales = Gross Sales - Discounts - Refunds