Mathematics Teachers’ Professional Competence Component Model and Practices in Teaching the Linear Functional Concept—An Experimental Study

Teachers’ professional development is now widely regarded as a key determinant of school effectiveness and student achievement. However, Mathematics teachers in Vietnamese secondary schools face numerous challenges in their teaching practices, such as a lack of recourse assistance, a lack of innovational teaching policy, and difficulty in using real-life examples in teaching. This study aims to identify Mathematics teachers’ professional competence components and organize a workshop to support Vietnamese teachers to enhance professional development through experiment research. A total of 40 postgraduate students on the master’s course of Mathematics Education at Saigon University are involved in this study. To reach the study objectives, we conducted three research cycles of: (1) Reviews to identify the model of Mathematics teachers’ professional competence for suitability in the Vietnamese context; (2) Developing materials and organizing the workshop on designing lessons that teach linear functional concepts in Grade 8 (13-year-old students); (3) Feedback analysis through a qualitative study with a group focus interview of 40 workshop participants. Data collection was recorded, and typed transcripts and theme development were employed in data analysis. The findings outline four criteria that serve as the cornerstone of our concept of professional competences for Mathematics teachers: I. Mathematical Knowledge; II. Interpretation of the Official Mathematics Curriculum’s Intentions; III. Understanding of Students’ Thoughts; and IV. Design of Teaching. This model was applied in materials design for the workshop and was highly appreciated and got a high level of satisfaction from participants. These findings are expected to bring benefits for stakeholders who are Mathematics teachers in schools or involved in Mathematics teacher education in higher education.