One of the most powerful tools in Excel is the Status Bar located at the bottom of your workbook. 



Multiple buttons are located on the toolbar:

Mode Indicator - when you first open a workbook, the word Ready is displayed in the lower left corner.  This will change to Enter as you type information in a cell and Edit when modify the information in a cell.
Record Macro - a Macro enables you to perform repetitive tasks that you can assign to a button or icon to use in the future.
Normal View - default view when working on a worksheet.
Page Layout View - enables you to change the layout, page orientation, set headers/footers, display or hide gridlines, show row/columns headings, and set scaling options.
Page Break Preview - similar to the Page Layout View but allows you to change page breaks and display Print Preview.
Zoom Controls - enables you to control the size of the worksheet for viewing purposes.

To Customize the Status Bar:
Right mouse click anywhere on the Status Bar to display the Customize Status Bar window.  Options that are selected will have a check mark next to them.  One of the neatest features is the ability to quickly calculate using the Status Bar.  Typically the Average and Sum feature are turned on by default.

To use the AutoCalculate Feature:
1.  Enter the following numbers in the corresponding cells:
         B2    100
         B3    200
         B4    300
2.  Select the range B2 through B4.
3.  Look at the lower right corner of the Status Bar.  You should see Average: 200 and
     Sum: 600!  

This option allows you to quickly calculate without completing a formula!  Remember this will 
work with cells not ajacent to each other as well.  To select non ajacent cells, select the first cell and then hold the Control key to select the other cells you are wanting to calculate.