Despite years of formal education, approximately one-third of all undergraduate students still cannot explain the causes of the seasons. Student manipulation of a handheld model is one approach to teaching this concept; however, the large number of students in many introductory classes can dissuade instructors from utilizing this teaching strategy. Students in large (n = 150) Earth science classes used a small, inexpensive model to explore the key concepts pertaining to the seasons and answered conceptually based conceptest questions using a personal response system. The numeric data demonstrated that students who used the model significantly outperformed students from two comparable control classes. Furthermore, classroom observations indicated that students used the models as a conceptual scaffold, and student interviews indicated that students preferred the model activities to the typical interactive lectures. (Contains 2 tables and 2 figures.)