The development of teaching material: Rigorous mathematical thinking in a geometry classroom

Abstract

This study aimed to develop a teaching material, a textbook, using a Rigorous Mathematical Thinking (RMT) approach. It was constructed by considering some activities involving problem-solving, problem posing, open-ended problem, connection problem, conjecture, creativity task, mini lab, and drawing skill. The subject in this study was the undergraduate mathematics students who enrolled in the geometry subject in the University of Wijaya Kusuma Surabaya. A textbook was developed because of the necessity. It was developed using the Mediated Learning Experience based on the Rigorous Mathematical Thinking. This study employed Plomp’s Research Design model consisting of three phases: the preliminary research, prototyping phase, and assessment phase. However, this paper focused only on the validation of the textbook involving five experts. Students have been mediated to construct their understanding by using mental operation. One important task about creative thinking including in the textbook dealing with the trapezium definition. Students were asked to create a new definition of trapezium which is different from the preceding definition they learned at school. The results showed that the development of student book using Rigorous Mathematical Thinking approach was valid.