Click A16. Type '='
![Click A16.](http://www.java2s.com/Tutorial/Microsoft-Office-Excel-2007Images/Enter_Function_Using_Function_Library___Click_A16.PNG)
Click the Formulas tab.
Click the button (Financial, Logical, Text, Date & Time, Lookup & Reference,
Math & Trig, More Functions, or Recently Used) from the Function Library
![Click the button (Financial, Logical, Text, Date Time, Lookup Reference, Math Trig, More Functions, or Recently Used) from the Function Library](http://www.java2s.com/Tutorial/Microsoft-Office-Excel-2007Images/Enter_Function_Using_Function_Library___Click_Button_financial_Logical_Text.PNG)
Click a submenu if necessary.
Then click the function to insert into a formula.
![Click a submenu if necessary. Then click the function to insert into a formula.](http://www.java2s.com/Tutorial/Microsoft-Office-Excel-2007Images/Enter_Function_Using_Function_Library___Click_Submenu_If_Necessary_Then_Cli.PNG)
Excel inserts the function you selected into the formula bar with a set of parenthesis.
And opens the Function Arguments dialog box.
![Excel inserts the function you selected into the formula bar with a set of parenthesis. And opens the Function Arguments dialog box.](http://www.java2s.com/Tutorial/Microsoft-Office-Excel-2007Images/Enter_Function_Using_Function_Library___Excel_Inserts_Function_You_Selected.PNG)
Type the argument or select the cell or range you want to insert in the function.
![Type the argument or select the cell or range you want to insert in the function.](http://www.java2s.com/Tutorial/Microsoft-Office-Excel-2007Images/Enter_Function_Using_Function_Library___Type_Argument_Or_Select_Cell_Or_Ran.PNG)
Press Enter to finish the input.
![Click OK.](http://www.java2s.com/Tutorial/Microsoft-Office-Excel-2007Images/Enter_Function_Using_Function_Library___Click_Ok.PNG)