The author discusses how to teach students to extend economic models using in-class scaffolding assignments, supported by discussions and workshops. Methods include discussions of a model's strengths and weaknesses; small group, in-class assignments that provide steps toward model extension; informal presentations of the work resulting from these assignments; and large group, post-presentation discussions in which students critique and build upon each other's work. Students then draw upon what they have learned to take one final step--to write a paper detailing a model extension. Although student model extensions do not reach a professional level of sophistication, students do extend models beyond what they know of them from textbooks and lectures. In doing so, students begin to create knowledge and to participate in economic discourse.