Before handing off the report, you want to add up the numbers in the Quantity column. That's easy — use the Sum button.
On the Home tab, it's in the Editing group. Place the cursor in the last cell in the Quantity column, and click the Sum button. Then press ENTER. Excel adds the numbers up by using the SUM function.
To do more than add, click the arrow on the Sum button. Then click any of the functions on the list that appears: Average, Count, Max, or Min. If you click More Functions, Excel opens the Insert Function dialog box where you can choose from all of the Excel functions. Or click the Formulas tab and check out the Function Library and Calculation groups.