Entering Numbers and Formulas

Excel accepts numeric values of all kinds. You can type positive numbers, negative numbers, numbers with decimal points, zero-leading numbers, numbers with dollar signs, percent signs, and even scientific notation (a shortcut for writing extremely large and small numbers).

Note

If you type a number but see something similar to 3.04959E+16 appear in the cell, Excel converted your number to scientific notation to let you know that the cell is not wide enough to display the entire number in its regular form. Excel does not extend long numbers into adjacent cells. Excel converts most numbers that contain more than 12 digits to scientific notation.

Excel right-justifies numbers inside cells. You can change the format for a single cell, a group of cells, or the entire worksheet, as you will see in Hour 8, "Using Excel 2003."

Perhaps the most important task in learning Excel is mastering formulas. You never have to do math in Excel because Excel does it for you. The trick is getting your formulas correct. Hour 7, "Reconstructing and Editing Excel 2003 Worksheets," explains the ins and outs of Excel formulas. Later in this lesson, you get a chance to create a simple worksheet. As you will see, if your data changes, Excel automatically recalculates the entire worksheet for you. Therefore, once you create a worksheet and enter all the formulas, you can concentrate on the data and let Excel do the calculating.

Entering Dates and Times

Excel supports almost every national and international date and time format. Excel uses its AutoFormat feature to convert any date or time value that you type to a special internal number that represents the number of days since midnight, January 1, 1900. As with all Office 2003 products, Excel automatically displays all dates the user enters with four-digit year values by showing the full year. Although this strange internal date representation of days since 1-1-1900 might not make sense now, you use these values a lot to compute time between two or more dates. You can easily determine how many days an account is past due, for example, by subtracting the current date from the cell in the worksheet that contains the due date.

Note

Excel uses a 24-hour clock to represent time values unless you specify a.m. or p.m. To convert p.m. times to 24-hour times, add 12 to all time values after 12:59 p.m. Thus, 7:54 p.m. is 19:54 on a 24-hour clock.

You can type any of the following date and time values to represent 6:15 p.m., July 4, 1976, or a combination of both 6:15 p.m. and July 4, 1976:

July 4, 1976

4-Jul-76 6:15 p.m.

6:15 p.m.

18:15

07/04/76 18:15

07-04-76 18:15

If you enter any of these date and time values, Excel converts them to a shortened format (such as 7/4/76 18:15). You can enter a date, a time value, or both. The shorter format often helps worksheet columns align better.

Navigating in Excel

Your mouse and arrow keys are the primary navigation keys for moving from cell to cell. Unlike Word, which uses an insertion point, Excel uses a cell pointer to show you the currently active cell. The active cell has a darkened border around it and accepts whatever data you enter next. As you press an arrow key, Excel moves the cell pointer in the direction of the arrow to a new cell, making the new cell the active one.

If you work with a rather large worksheet, you might find the Go To command useful. Press F5 to display the Go To dialog box, where you can select a range of cells that you might have previously named or type a cell reference value such as C141 to jump to that cell.

Table 6.1 lists the most commonly used navigational keystrokes within Excel. Use your mouse to scroll with the scrollbars. To scroll long distances, press Shift while you scroll with the mouse.