We began the unit by considering the movement of dynamically changing roots of a
quadratic equation as one of the parameters of the quadratic was varied, and using the complex
plane as a tool to investigate that motion. After students began to view complex numbers as
points in the complex plane, they were asked to invent ways to geometrically add and multiply
complex numbers. Finally, students engaged in tasks where they were asked to view complex
arithmetic as a method of achieving transformations on other complex numbers in the complex
plane. In terms of the emergent model heuristic from RME, we conjectured that the complex
plane would initially serve as a model-of complex roots to quadratics, and later serve as a modelfor
transformations on the complex plane.