Show Calculations Property
Another important property is Show Calculations. In the Key Browser, set the Show Calculations property to 'true' and expand Datasources. You'll see the 'count' key was added under Datasources. A 'count' is the total number of rows in your Datasource. Expand your columns and you'll see that a number of built-in keys were added. For each column you can calculate the following: value, total of all the values in that column, average, maximum value, minimum value, running total, and running average. These keys are available for each column that you bring into your table once you set Show Calculations to 'true'. The Show Calculations property can come in pretty handy once your familiar with how it works.
Drag one of the keys over to the table and you'll notice the value or total or whatever shows up. You can also create another row for the summary information, create titles (i.e. Total, Summary) and bold it so it stands out. Not recommended for text strings, but for showing calculations this is great.