A formula is an equation that calculates a new value from existing values. In Chapter 15, you learned how to build simple formulas using numbers and cell references, and in Chapter 18, you expanded your skills by creating formulas that linked to cells from other worksheets and workbooks. In this chapter, you'll discover how to build more sophisticated formulas. You'll learn how to use arithmetic operators and parentheses to control how your formulas are evaluated, you'll explore techniques for replicating formulas, and you'll practice using range names to make your formulas more readable and easier to modify. In addition, you'll learn how to use Microsoft Excel's impressive collection of built-in functions for specialized tasks such as totaling columns, computing averages, and calculating the monthly payments for an auto loan. Using well-organized formulas and functions, you can evaluate business data in new ways, spot important trends, and plan your financial future.