SPREADSHEETS

Spreadsheet software is one of the most-used technologies for collecting, computing, and displaying data. Spreadsheets contain a rectangular array of cells in rows and columns that can hold data. Users can create business models, graphs and charts, and reports for financial, statistical, or other data. Most spreadsheet software allows a user to access real-time data from Web sites and to collaborate across teams and workgroups.

SPREADSHEET PACKAGES

Spreadsheet packages are available for various operating systems, such as Windows, Macintosh, UNIX, Java, Linux, and VMS. Spreadsheet capabilities are included in financial management packages and integrated software packages. The best-known spreadsheet software packages are Microsoft Excel, Lotus 1-2-3 from IBM Corporation, and Corel's Quattro Pro. These three packages are included as parts of office suites from Microsoft, IBM, and Corel.

In addition, dozens of other spreadsheet packages are available. Many of these offer users an opportunity to try the product for a limited period and then pay a fee for permission to use the package beyond the evaluation period. Many spreadsheets are listed on the Internet by their developers, either as shareware or for purchase, and some are available for downloading.

SPREADSHEET APPLICATIONS

A spreadsheet is a table representing information in worksheet form. The spreadsheet can be visualized as a large sheet of paper with rows and columns and is based on the worksheets used by accountants for manual computations.

Sales by region for first quarter
	January	February	March	Total
East	$ 1,200	__BODY__,500	__BODY__,800	$4,500
Midwest	500	1,000	1,500	3,000
South	900	1,500	1,800	4,200
West	2,000	2,100	2,400	6,500
Totals	$4,600	$6,100	$7,500	$18,200

Spreadsheets range from small, simple text tables to large documents that can carry out complex computations and statistical analysis of thousands of data entries.

Simple spreadsheets can be displayed on screen; more complex spreadsheets extend into vast numbers of cells and can be displayed in part on one screen. The power of a spreadsheet is in its ability to store formulas and display their results. A recalculation feature in spreadsheets allows a user to enter new data into the spreadsheet—which can affect other sections of the spreadsheet—and see the results of new calculations. This "What If" feature of spreadsheets is a valuable tool for users.

FORMAT OF A SPREADSHEET

Spreadsheet software packages organize numeric data into table format, vertically in columns and horizontally in rows. Three types of data may be entered into a spreadsheet or worksheet: (1) values or numbers, (2) names or labels, and (3) formulas for calculation. Values may be used for basic arithmetic operations: addition, subtraction, multiplication, or division. Labels identify information in the worksheet and organize the information. Formulas perform calculations on data and display and store the resulting values. A cell, the intersection of a row and column, can contain a label, a value, or a formula for performing calculations. Cells are addressed by column number and row number, and a current cell address is displayed in an address box. The "home" cell is A1, located in column A, row 1.

Only a small part of a complex spreadsheet is displayed on the screen at one time. Spreadsheets can contain millions of cells in each spreadsheet, and a spreadsheet file can include multiple spreadsheets. For example, Lotus 1-2-3 and Microsoft Excel spreadsheets have 256 columns and 65,536 rows, or 16,777,216 cells. A spreadsheet file also may include multiple worksheets. More than one worksheet can be used to render three-dimensional charts of data. Spreadsheets are very powerful, extensive electronic worksheets.

A spreadsheet handles such simple functions as adding, subtracting, multiplying and dividing. Arithmetic operators are used to represent the functions: addition (+), subtraction (–), multiplication (*), and division (/). For example, an entry into cell D3 of "=B3+C3" would instruct the spreadsheet to add the contents of cells B3 and C3 and store the sum in cell D3. A symbol at the beginning of a formula identifies the entry as a formula instead of a label. In an entry of =B3+C3, the equal sign identifies the entry as a formula.

A simple spreadsheet can be enhanced with spreadsheet tools. Font faces (e.g., italic or bold), sizes, and types can be changed, color can be added to the background of cells or labels, and graphs can be used to illustrate data from the spreadsheet.

A spreadsheet is initially set up by default with a given column width, row height, and format for entries. If labels are longer than the column width allowed, the spreadsheet does not "lose" the extra characters; instead they are not displayed if the cell to their right has an entry. The user may change the column width and row height to enhance the appearance of the entries. Values are stored by the spreadsheet in their simplest form initially; an entry of __BODY__,050.00, for example, can be stored as 1050. The user then has tools within the spreadsheet for formatting entries.

Numeric data may be formatted as dollars and cents, with commas separating hundreds and thousands, in various formats for different countries, with a given number of decimal points, in exponential form, or in other formats. When a formula is entered, the cell displays the result of computation and retains the formula. To display the formula, not its results, in a cell, a user can choose a format for "text." A formula that is entered as +=C3+D3–E3, for example, might show a result of 25. If the cell is formatted to the "text" format, the formula will show instead of the computed answer. Spreadsheet packages usually have a "shortcut" keyboard method of displaying the formula version of entries.

A set of data can be described to the spreadsheet as a range by specifying the beginning cell, in the upper left corner of the data, and the ending cell, in the lower right corner of the data. For example, to identify a rectangle that begins with cell A1 and extends down to cell D3, one address for the range would be A1:D3. Spreadsheets identify the range with a symbol that means "through." In the example A1:D3, the format used by many spreadsheets, the range is interpreted as "cell A1 through cell D3."

An example of a spreadsheet is shown in Figure 1. Rows 1 through 7 show a spreadsheet. In row 1, "Sales by Region for First Quarter," the heading for the entire worksheet, is an example of a label. The column headings and items in column A are labels; columns B through D are

values, which are summed in column E with formulas. The formulas in column E sum the numbers for January, February, and March for each item. Across the bottom of the spreadsheet, the total line is also a result of using formulas to sum the columns. The formula for E3, for example, is =SUM(B3:D3).

The title, "Sales by Region for First Quarter," and the column headings (January, February, March, Totals) show how font changes can enhance the readability and attractiveness of a spreadsheet. Cells can be formatted to bold, underline, or italicize entries; background color or shading can be added; and font faces and sizes can be changed. In the sample worksheet, formatting has been used to aid readability.

Values can be formatted. In the sample spreadsheet, the values in rows 4 through 6 have been formatted to no decimal places with commas. Rows 3 and 7 have been formatted with a dollar sign for readability. A user can select the desired formatting from a menu.

Spreadsheet data can be selected for charts, or visual representations of those data. Cells are selected by highlighting them. Spreadsheet packages may chart one set of data in the form of a pie chart, or two or more sets of data in bar charts (with vertical bars, horizontal bars, or stacked bars), line charts, area charts, or mixed charts, which combine bars and lines to represent data. Data can be displayed in two-dimensional or three-dimensional form. Charts become part of the spreadsheet and may be stored on the same page as the spreadsheet or as a separate page or worksheet. Figure 2 shows a sample chart for the sales spreadsheet described above.

The chart depicts the figures from B3 through D6 in the spreadsheet, categorized by cells A3 through A6 (labels). A column (or bar) chart is only one of several choices of charts that a user can select. The software provides steps for adding a title to the chart, a legend, and/or a listing of labels for the charted data.

MACROS IN SPREADSHEETS

A macro is a series of commands that automate a spreadsheet task, streamline complex procedures, or create applications. A user can enter a macro into a worksheet file or into a macro library, a worksheet file that stores macros. To create a macro, the user enters the steps needed to carry out a task, gives the macro a name, and saves it in a file. To use the macro, the user selects it by name from a menu and runs the macro in the spreadsheet. The steps are carried out automatically. For complex tasks that are used often, a macro makes it easier for a user to avoid mistakes in the task, since the steps are stored as a file and recalled as needed.

SPREADSHEETS IN INTEGRATED PACKAGES

Integrated software packages, which contain several kinds of software within one, include a spreadsheet. Information can be copied from a spreadsheet into other software packages, such as a word-processing package. Spreadsheets can be linked to files in other software in the package so that changes made in the spreadsheet are automatically reflected in the linked document. A table from a spreadsheet can be linked to a word-processing document so that any changes in cell entries in the spreadsheet change the contents of the table in the word-processing document.

Embedded objects, such as a chart from a spreadsheet, can be embedded into a word-processing document. Unlike linking, changes in the embedded chart in the document are not reflected in the source file (spreadsheet file). These features make the spreadsheet a very powerful tool for analysis and reporting of data in various formats.

SUMMARY

Spreadsheets are used by almost every business firm that records data. Spreadsheets have also become a useful tool for personal record keeping. The data organization and graphics capabilities of spreadsheets make them a useful tool for all types of calculations, displays, and analysis.