The two research questions that frame the research in this book are (1) How do preservice teachers develop mathematical knowledge for teaching during a coordinated math methods course and field experience? and (2) What types of portfolio tasks lend themselves to documenting mathematical knowledge in teaching? Six female elementary (K-8) teacher candidates were the participants in this research. The six teacher candidates all completed their field experiences in the same K-8 school, St. Joseph, in Lockport, Illinois. Three of the teacher candidates had elementary placements (grades K, 1, and 4) and three of the teacher candidates had middle school placements (5, 6, and 7). Each of the teacher candidates completed pre-test and post-test DTAMS assessments. All candidates taught three consecutive mathematics lessons. After each lesson was taught, a debriefing interview was conducted. Each teacher candidate submitted a Math Teaching Portfolio. Results illustrated the growth of mathematical knowledge for teaching that occurred for each participant. Implications for the field of mathematics education, future research, and teacher preparation programs are also discussed.