This study aims to examine elementary school teacher candidates’ content knowledge competencies in mathematics. The study was conducted by using both qualitative and quantitative research design models. The participants of the study consisted of 100 elementary school teacher candidates. The study consisted of three phases. In the first phase, the participants were asked to fill out the Teacher Candidates Professional Competencies Scale. Then, 15 groups were created for cooperation. Each group was asked to design a lesson for second graders about “addition” by considering the objectives in the elementary school mathematics curriculum. In the second phase of the study, those activities were reviewed by elementary school teachers. Each teacher received only one lesson plan. After reviewing them, they were asked to apply them in their classrooms. At the end of this phase, the teachers were asked to write a report about the lesson plans they received. This process lasted three weeks. In the third phase, the teacher candidates revised their lesson plans based on the teacher reviews. In addition, in order to determine the professional competence levels of pre-service teachers, teacher candidates' perceptions of their professional competencies level scale was used. The data was examined in the context of self-efficacy in professional competencies. As a result, teacher education programs must be re-structured in order to support students’ inadequacies in terms of professional competencies.

Keywords: Elementary school teacher candidates, professional competencies in mathematics, constructive approach