Methods for teaching early childhood mathematics and science are often addressed in a single, dual-content course. Approaches to teaching this type of course include integrating the content and the pedagogy of both subjects, or keeping the subject areas distinct. In this article, the authors discuss and illustrate their approach to such a combined course. They emphasize the development of preservice teachers' distinct pedagogical content knowledge in mathematics and in science rather than an integration of the two. The authors do this by concentrating their course development on a central unifying theme or idea within each content-area. Through course readings, media, in-class activities and discussions, and fieldwork, the authors highlight the similarities and differences between early childhood mathematics and science methods, thus offering preservice teachers a conceptual infrastructure that empowers them to make informed choices about their own mathematics and science programs.