A simple formulation of Milankovitch theory, relating the balance between growth and melting of ice to summer insolation at 65°N latitude, is useful in making numerical experiments on iceage climate in a standard spreadsheet. The experiments allow students to familiarize themselves with the basic tenets of the theory, while learning about the central questions of Quaternary geology and climate. The experiments are designed to foster appreciation for the complexity of climate dynamics which can arise from the interaction of but a very few basic processes. The concepts of “system,” “model,” “input,” “target,” “forcing,” “response,” “feedback,” “instability,” “oscillation,” and “stepwise numeric integration,” among others, are clarified through experimentation.