Quantitative reasoning is a key intellectual skill, applicable across disciplines and best taught in the context of authentic, relevant problems. Here, I describe and assess a laboratory exercise that has students calculate their "carbon footprint" and evaluate the impacts of various behavior choices on that footprint. Students gather…

"How the World Works" is an interdisciplinary science and mathematics course in which students design and perform their own experiments, analyze the data, and present their results orally and in writing. Evaluations indicate that most students learn how to do science and gain a better appreciation for science as a process. (SAH)