Standardized testing has elementary schools transitioning into departmentalization, where a teacher is assigned to teach a particular subject matter. Elementary education programs tend to provide a holistic approach to education that includes training in all subject matters and learner psychology. The national trend of teacher shortages as resulted in the hiring of teachers who have not attended a formal education preparation program. Departmentalized elementary teachers in mathematics enter the role without prior specialized training due to holistic teacher preparation programs or entering the profession from another role. This study explores the implementation of pedagogical content knowledge of departmentalized elementary mathematics teachers in a large urban district during planning and instruction. Pedagogical content knowledge is the specialized content knowledge needed to effectively instruct a subject matter. Through multiple case study design, this exploration was able to identify specific elements of pedagogical content knowledge evident in the lesson plans, class observations, and interviews with seven elementary mathematics teachers in a large urban district. The findings provide insight on the various levels of planning in the area of questioning, but a consistency of evidence in the areas of multiple representation and problem selection. Despite the inconsistent evidence of planning for productive questioning, the elementary teachers demonstrated evidence of asking productive questions throughout the lesson and responding to student errors. The participants during the interview expressed the desire to increase the level of purposeful reflection on their planning and instruction as a way to improve their craft. Implications of these findings are discussed for school-level professional development programs and district-level structures for continuing education for departmentalized elementary mathematics teachers. This study contributes to the exploration of pedagogical content knowledge and teacher development specifically in the elementary setting and departmentalization that can be supported through collaborative structure and formalized reflections. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]