spread sheets

The utility of a spreadsheet application lies in the formulas and functions that the user is able to perform. A formula is simply an equation created in a cell that uses data from other cells to generate new information. Formulas and functions simplify the application of these equations for the user. For example, if you knew that seven people were attending a dinner that had a cost of $10 per head, you could figure out the total cost for the dinner without using a spreadsheet by multiplying seven and ten for a result of $70. If the number of people attending the dinner changed to nine and the cost went down to $8.75, you could again multiply the numbers to figure the total cost of the meal; however, for most people, this calculation would be more difficult. Using a spreadsheet allows the user to create a formula to do this work so that the variables involved—such as the number of people attending the dinner and the cost of the dinner—could change as much as necessary, and the user would only have to write the formula once. Entering Formulas and Cell References Before entering a formula, always ensure that the cell that should display the results of this formula is the active cell. Numbers that represent specific values should never be directly entered into a formula; instead, use cell addresses to refer to the data used in the formula. Because of the fact that formulas in Excel begin with an equal sign, begin your formula by entering an equal sign in a cell to define it as active. Once the cell is active, you may define the cell or cells to be used in the formula. Two types of cell references are used in constructing a formula in an active cell: relative and absolute. Relative cell references are references that change depending upon the location of the formula on the spreadsheet. If a formula that includes relative cell references is copied to another cell, the cell references will change according to the location of the formula on the spreadsheet. Absolute cell referencing is used to make a cell reference remain static and not change according to the location of the formula. This is done to prevent cell references from changing when formulas are moved or copied. Operators, Order of Operations, and Range Names Excel includes many useful features and tools. Arithmetic operators in Excel may appear familiar: addition and subtraction signs are standard, multiplication � is signified by an asterisk, and division is symbolized by a forward slash. Range names—which can be a single cell or multiple adjacent cells—improve the readability and organization of formulas. Functions Functions in Excel are simply prewritten formulas. Some of the more commonly used functions are found by clicking on the AutoSum button located in the Function Library Group on the Formulas tab. It is often challenging for less experienced users to understand the amount of data presented or required in the use of an advanced function; in this situation, using the Insert Function dialog box to create functions will provide the user with complete descriptions of all functions and the individual inputs that are built in to Excel. The Insert Function dialog box is found in the Function Library group on the Formulas tab. Multisheet Workbooks Using multiple sheets within your workbook allows users to use large amounts of data and to separate that data into categories. Excel lets users link data on separate sheets; this type of reference created is called a 3-D reference, and it is used to perform complex operations within a workbook. �