Teacher Education Programs (TEPs) are intended to prepare students to become qualified professionals in the field of education. Yet, many preservice teachers (PSTs) have difficulty recognizing their new roles, not simply as students in the TEP, but as future educators. As PSTs progress through their coursework, field experiences, and student teaching, their perceptions of teacher knowledge evolves. Teacher educators may assist in positively influencing such transformation through reflective exercises, learning activities, and thoughtful discourse. The present research examines four classroom discussions centered on a mathematics and science activity. These discussions illustrate the changes in perspective with respect to mathematics and science teacher knowledge, among a cohort of elementary PSTs between the beginning and end of their first year in a TEP.