The National Council of Teachers of Mathematics (NCTM) has called for changes in mathematics teaching from a procedural to conceptual focus since 1980, yet the way mathematics is taught in many classrooms continues to contradict the recommended practices. The pervasiveness of this challenge has led some educators to suggest changes in university teacher preparation so that educators blend coursework with fieldwork and facilitate the simultaneous development of conceptual and practical tools. Mathematics teacher educators are just beginning to study the impact of blending university instruction with experiences teaching students. The current study of transforming a mathematics teacher education course investigated the conceptual and practical understandings preservice teachers constructed and their process of learning through this blended course experience.