Mathematics Teachers’ Noticing during the Proof and Proving Lesson Planning: Focusing on the Property of the Isosceles Triangle

Source abstract

This study explored middle school mathematics teachers' noticing in the context of planning proof and proving lessons on the properties of isosceles triangles. A qualitative case study involving two middle school mathematics teachers was conducted. The findings showed that both teachers attended to instructional aspects related to organizing students' justification activities, while their interpretations differed in terms of mathematical and student-focused considerations. In the responding, both teachers designed questions and selected tasks intended to support students' justification activities and deepen their understanding of the properties of isosceles triangles. The study illustrates how teachers' noticing is manifested in the context of planning proof and proving lessons and offers implications for the design of instructional strategies that foster students' justification activities.