You can use the [AGE] field in both columns, this way you will by default get a field named [Count of AGE] when the query is ran.
Kaloka, although your link is technically correct, for someone that doesn't know how to write SQL, which is what OP's post indicates, the following link may be a better fit:
Count data by using a query (ACC2007/2010)
The process is much the same in earlier versions; however, the location of total toggle varies a little bit.