Excel is a powerful program with more than 300 built-in functions that can be used to perform an almost infinite number of calculations. This friendly book shows you how to use the 150 most valuable ones in real-world situations: to compare the cost of buying vs. leasing a car, calculate classroom grades, or evaluate investment performance, for example. Another 85 specialized functions are also described. Detailed, step-by-step instructions help you understand how functions work within formulas and how you can use them to solve everyday problems