This University of New Hampshire project entitled: Learning Mathematics through Teaching proposes to develop new curriculum modules for an existing undergraduate level course for future secondary teachers that are based on experiences with student difficulties in this course, as well as on current literature on mathematics teacher preparation. In addition the project provides prospective teachers with a practicum experience with experienced teaching assistants who have been trained in mentoring preservice teachers and in planning and facilitating classroom practices. It is also developing, implementing, and carrying out research on a professional development program for teaching assistants who instruct precalculus. These teaching assistants are being trained in facilitating inquiry-based student-centered teaching strategies.