These notes discuss several related problems in geometry that can be explored in a dynamic geometry environment. The problems involve an interesting property of hexagons.

Lines and angles are essential for students because of geometry and its many applications in daily life. However, there are still many students who have difficulty grasping the material. Therefore, it is necessary to design learning using the right approach, context, and media. This study aims to produce a learning trajectory that can assist…

Many students share a certain amount of discomfort when encountering proofs in geometry class for the first time. The logic and reasoning process behind proof writing, however, is a vital foundation for mathematical understanding that should not be overlooked. A clearly developed argument helps students organize their thoughts and make…

The relationship between teacher interventions and students' mathematical thinking has been the subject of inquiry for quite some time. Using the Pirie-Kieren theory for dynamic growth in mathematical understanding, this study documents teacher interventions that support students' growth toward developing a general understanding of a mathematical…

In this article, the authors explore a number of interesting games as contexts for students learning geometry and enhancing their development of problem solving and reasoning. The games selected were appealing, content-aligned games for approximately four players with simple rules and 10-30 minutes of play time. The games were integrated by…

Valid proofs need not be in the traditional two-column format. This classroom activity allows students to explore, discuss, and use specialized facts to create a general statement of truth.

In this article, we describe one possible way to modify volume tasks in textbooks to promote conceptual understanding of the volume formula: length × width × height. From the results of previous studies regarding students' understanding of volume measurement, we identified three conceptual ideas key to understanding volume: filling…

This article explores three processes involved in attending to evidence of students' thinking, one of the Mathematics Teaching Practices found in "Principles to Actions: Ensuring Mathematical Success for All." These processes, explored during a classroom activity on proportional relationships, are discussed in this article, another…

The aim of this study was to investigate the effects of modelling, collaborative and game-based learning on geometry success in third-grade students. These approaches were applied to geometry instruction in nature on the success of students in geometry. The students' views about geometry activities were also examined. Explanatory design, one of…

This article presents some paper-folding activities for students to explore a different way to prove some of the angle properties in a circle.

In this work, we study the mathematical practice of defining by mathematics researchers. Since research is an important part of many professional mathematicians, understanding how they do research is a necessary step before thinking about future researchers' undergraduate and postgraduate education. We focus on the defining process associated with…

The effect of using Geoboards in teaching Euclidean geometry in Grade 11 mathematics learners is described. A qualitative research design was adopted in the study. This design was preferred as it provides the conceptual understanding of the teaching methods of the teachers. The participants were taught Euclidean Geometry with the use of Geoboard…

Middle school mathematics teachers often do not emphasise statistics and geometry in their lesson plans for a variety of reasons. However, these are integral topics in mathematics, and using direct lecture or hands-on activities may have different effects on teacher confidence when approaching these subjects. Using qualitative and quantitative…

In this study, we examined and compared volume and volume-related lessons in two common core aligned U.S. textbook series and Korean elementary textbooks. Because of the importance of textbooks in the lesson enactment process, examining what textbooks offer to students and teachers is important. Since different parts of a textbook provide…

This study examined pre-service teachers' views and experiences of building geometric constructions on paper and with the interactive whiteboard. The study group consisted of 26 pre-service elementary teachers in a state university in the Black Sea region of Turkey who took the Geometry Teaching course. The data were obtained from an opinion form…