A case study on the semiotic signs during a lecture of Cartesian plane

The use of signs in the teaching of mathematics plays a crucial role in students' cognition. Trying to understand what signs both students and teachers use in the mathematics classes may help us understand their meaning making processes. From this point of view, this paper aims to reveal the use of semiotic resources both by students and a teacher while lecturing Cartesian plane in seventh grade level. The study group of this qualitative study consisted of a teacher and her 29 seventh grade students. Two lectures delivered by the teacher on the Cartesian plane have been video-recorded. The semiotic analysis to make meanings from the linguistic and visual signs expressed through gestures and discourses has been conducted. According to the analysis of the data, links were explored between the signs in the class to present what the students and teacher actually were trying to say and how the signs used were reflected on the other side. What is more, the unclear directions and the in\-con\-sis\-ten\-cies between the discourses and gestures of~the teacher misled the students' thinking, which was revealed during the mathematical tasks. It seems that the teacher assumed that students think the same way with her.