An economic principles professor typically draws a graph on the chalkboard, explains its construction, and then uses the graph to analyze the effects of various changes in the model's parameters or variables. Because the classroom explanation and manipulations usually happen only once, the logical progression of the economic model can be difficult for students to replicate. Textbooks, limited to written explanations and static illustrations, cannot capture the step-bystep dynamics and application of an economic model. By manipulating elements of Web-based interactive graphs and receiving immediate feedback, students can understand basic economic principles. They can repeat each model's dynamics as often as necessary to comprehend the economic principle. The ThinkEconomics Web site contains interactive graphs that can be used to analyze and explain changes in supply and market equilibrium, the construction of the long-run average cost curve, short-run profit maximization for a perfectly competitive firm, long-run market equilibrium under perfect competition, changes in aggregate demand and aggregate supply, and monetary fiscal policy in the aggregate demand and aggregate supply model (and with a money market graph). Students can control animation, drag curves, make choices, observe results, and receive feedback. The graphs require the installation of the FlashTM plug-in. This approach to working with economic models facilitates the development of analytic and deductive reasoning skills. Animation and interactivity combine with the accessibility of the Web to create a greatly improved learning environment.