Final answer:
To use aggregate functions in a query, you would generally include them in your SELECT statement, not through a specific button. Software with a graphical interface, like Microsoft Access, does offer a 'Totals' button in the query design view where you can select aggregate functions. Exact methods may vary with different software, so consulting specific documentation is recommended.
Step-by-step explanation:
To use aggregate functions in your query within a database system, such as SQL, you need to incorporate them into your SELECT statement. Aggregate functions perform a calculation on a set of values and return a single value. Examples of these functions include SUM, AVG (average), MIN (minimum), MAX (maximum), and COUNT. When writing a query in a program like Microsoft Access or using SQL, there isn't typically a specific button to use aggregate functions; instead, they are written as part of the SQL query.
However, if you are using a graphical interface such as Microsoft Access, you can use the 'Totals' button in the query design view to add a row for aggregate functions. You can then select the desired function from a dropdown list in that row for each field you want to apply the function to. In Microsoft Excel, you might use the 'Subtotal' feature under the 'Data' tab for similar functions.
Remember, the exact method to apply aggregate functions can vary depending on the software and version you are utilizing. Hence, it's essential to refer to the specific documentation or help resources provided with the software you're using for the most accurate and updated instructions.