Robert,
Using the query design grid, select View/Totals from the main menu, and place Sum in
the Total row of the field you want to add up.
By the by, when you use the query design grid, you're really creating SQL statements.
Check out View/SQL on any query and you'll see the SQL equivalent of your query. So, it's
easy to design using the grid, but you can also cut and paste the SQL statement from that,
and use it in a module.