Sequences are an important topic--not only in mathematics but also in the mathematics curriculum. Exploring sequences related to medial triangles offers learners opportunities to solve problems involving sequences within geometric contexts. Sequences related to medial triangles are also a rich source of beautiful and interesting geometric patterns…

This case study investigates prospective middle school mathematics teachers' use of the Angle tool in GeoGebra, focusing on reflex angles in a geometric construction task. They constructed a parallelogram with individual heights for any two consecutive sides. We analyzed their screencasts to identify the ways in which they used reflex angles in…

This study investigates the effectiveness of a teaching activity that aimed to convey the meaning of indeterminate forms to a group of undergraduate students who were enrolled in an elementary mathematics education programme. The study reports the implementation sequence of the activity and students' experiences in the classroom. To assess the…

This article is based on a study that documented the daily work practice of an eighth-grade mathematics teacher and her colleagues at a secondary school in Shanghai when they taught the unit on geometric proofs. Four interrelated work activities were identified to highlight a pedagogy around homework errors. They form an activity system…