Abstract.

This study aims to present mathematics teachers’ pedagogical content knowledge about students' thinking and misconceptions related to examples of quadrilateral shapes. This research is case studies of two junior high school mathematics teachers. The focus of this research is the teacher's knowledge of students' thinking and misconceptions related to the examples of quadrilateral shapes and how to eliminate the misconceptions. Data gathered from the teachers’ written analysis of students’ work on quadrilaterals and the in-depth interviews based on the written analysis. Data were analyzed using Constant Comparative Method. The result indicated that the teacher's knowledge of students' thinking and misconceptions is that students' understanding of quadrilateral examples is limited to the standard quadrilateral examples. Both teachers found that most students only chose standard quadrilateral shapes (prototype examples). According to the teachers that the misconception was caused by teachers’ strategies in giving the examples. Both teachers only gave prototype quadrilateral examples as presented in the textbooks used by them regardless the variation in either the comparison of side-sizes of quadrilaterals or the images’ orientation. However, both teachers planned to provide more varied examples in order to eliminate students’ misconceptions.

Key words: Pedagogical content knowledge, prototype examples, quadrilaterals