Excel's Insert Function dialog box and Formula palette make it easier for you to use and understand functions by organizing them into logical categories and by prompting you to complete the arguments required to make the function return a correct value.
The Insert Function dialog box and Formula palette can be accessed in several ways:
Click the Insert Function button (the fx button)) on the Formula bar.
Click Insert in the menu bar and choose Insert Function.
Type the equal sign (=) and name of the function in a cell and press Ctrl+A. Then enter the arguments in the Function Arguments dialog box.
Click the Function down arrow button at the far left end of the Formula bar and select a function from the Function list.
When you use any of these methods except for the last two in the list (the Insert Function button [the fx button] on the Formula bar), Excel displays the Insert Function dialog box, as shown in Figure 15.1.
From this dialog box, you choose a function, click OK, and the Function Arguments dialog box opens (see Figure 15.2).
The most recently used category of functions appears in the Category list in the Insert Function dialog box. This feature is especially handy when you use a particular group of functions frequently. The list changes and keeps the last 10 functions you used. When a function is highlighted in the list on the right, its name, a brief description, and its arguments are displayed below the Category list.
After you select a function in the Insert Function dialog box, just click OK. This brings you to the second step, which is entering arguments or instructions for calculation in the Function Arguments dialog box.
You can use the keyboard or the mouse to enter arguments that require cell addresses or ranges. Other arguments that are not associated with specific cells on the worksheet must be entered manually. Some arguments are required for a value to be returned, and some are optional. Arguments that are required appear in bold. Optional arguments appear in regular typeface. In Figure 15.2, you enter a range of cells in the Number 1 text box.
If you need help with a particular function while you're in the Function Arguments dialog box, click the Help button. Excel's Help Assistant walks you through the particular function with which you are working.