This lesson begins with a review of linear functions and segues nicely over its fifteen examples and problems into a deep study of exponential functions. Linear and exponential growth are compared in an investment task. Data tables are used to explore and practice the idea of common ratios to recognize exponential functions. Graphing calculators assist learners in finding the characteristics of an exponential function and the calculating of inputs and outputs of functions is described and practiced. Finally, learners practice writing exponential equations from given data.