Jay Lehmann is passionate about answering the question so many math instructors hear their students ask: But what is this good for? He discovered that a curve fitting approach could enable students to see how math is used in all walks of life with current, compelling, and authentic situations. In addition to curve fitting, Lehmann's approach includes other types of meaningful modeling, directed-discovery explorations, conceptual questions, labs, and of course, a large bank of skill problems. The curve fitting applications serve as a portal for students to see the usefulness of mathematics so that they become fully engaged in the class. Once involved, they are more receptive to all aspects of the course.