Decades of scholarly work continue to document the marginalization of children from nondominant backgrounds in mathematics classrooms. Learning to equitably teach children from linguistically, ethnically, racially, and culturally diverse backgrounds remains a priority. This dissertation approaches this broader problem in society by understanding how to prepare elementary teacher candidates to center equity in their mathematics teaching. The first study explores how an innovative pedagogical activity elicits and has candidates confront their expectations, assumptions, and biases about children and their mathematical thinking. The study conceptualizes a framework that captures the extent of candidates' self-awareness of their assumptions and biases. The second study conceptualizes teacher candidates' conceptions of equity in mathematics teaching and explores their prior mathematics experiences. The third study tells the story of how a researcher-practitioner collaboration developed and shifted the mathematics course to integrate an equity lens over time. Research data include candidates' written reflections, interviews, and other artifacts they produced in the methods course; field notes of class observations; teacher educators' interviews and syllabi; and other documentations of idea exchanges between the teacher educator and researcher. Qualitative analytic methods were employed. The study findings reflect the importance of self-confrontation and critical self-reflection in a mathematics methods course to support candidates to center equity in their practice. The three studies contribute to the field of teacher preparation in the following ways: (1) a conceptual framework for candidates' self-awareness of their biases and assumptions and a conceptual framework for centering equity in mathematics teaching; (2) a typology for teacher candidates' conceptions of equity in mathematics teaching and a more nuanced understanding of candidates' prior mathematical experiences; (3) an illustrative example of how a collaborative relationship between a researcher and practitioner developed over shared sensemaking experiences. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]