This paper discusses the extensions that we have made to Betty’s Brain teachable agent system to help students learn about dynamic processes in a river ecosystem. Students first learn about dynamic behavior in a simulation environment, and then teach Betty by introducing cycles into the concept map representation. Betty’s qualitative reasoning mechanisms have been extended so that she can reason about cycles and determine how entities change over time. Preliminary experiments were conducted to study and analyze the usefulness of the simulation. Analysis of the students’ protocols was very revealing, and the lessons learnt have led to redesigned simulation interfaces. A new study with the system will be conducted in a fifth grade science classroom in May, 2005.