In the mathematical literature on analytical geometry, various notions of the conics' eccentricity correspond to different approaches to these curves. After making a comparative analysis of well-known textbooks to determine coincidences and differences between the various concepts of eccentricity, as well as how the authors explain the…

As a component of a course on geometry for preservice elementary teachers (PSTs), we derive area formulas for a variety of polygons including triangles, quadrilaterals, and both regular and irregular shapes whose areas can be measured empirically using decomposition. Decomposing a circle to justify why its area can be measured using the standard…

Geometric experience, spatial representation, spatial visualization, understanding the world around us, and developing the ability of spatial reasoning are fundamental aims in the teaching of mathematics. (Freudenthal, 1972) Learning is a process which involves advancing from level to level. In primary school the focus is on the first two levels…

This study is about student teachers' conceptual understanding of shapes. While the National Curriculum Statement stipulates that by the time learners exit high school they should have grounded knowledge of basic geometry and know shapes such as polygons and polyhedrons and their properties, this study finds that the majority of student teachers…

This report summarises a study examining preservice elementary teachers' geometry content knowledge with a focus on parallelogram. It was a descriptive study examining 45 preservice teachers' reasoning in the process of determining which quadrilateral can be classified as a parallelogram. Findings have revealed that these elementary teachers do…

The GeoGebra Workshop for the degree "Teacher in Primary Education" has been designed to work the main geometric competencies that primary pre-service teachers need to develop. In this paper, some case studies are included in which we analyse the development of geometric skills and the use of GeoGebra dynamic tools in three types of activities:…

The main goal of the Learning and Teaching Geometry (LTG) project is to build professional development (PD) materials that provide opportunities for teachers to engage in learning about geometric similarity through the use of video cases, in which specific and increasingly complex mathematical ideas are presented within the dynamics of classroom…

Recognizing and responding to students' thinking is essential in teaching mathematics, especially when students provide incorrect solutions. This study examined, through a teaching scenario task, elementary preservice teachers' interpretations of and responses to a student's work on a task involving reflective symmetry. Findings revealed that a…

The lack of mathematical understanding of elementary preservice teachers with respect to many mathematical topics has been well documented. Far fewer studies have been conducted on any content area of knowledge of secondary teachers and even less in the mathematics content area. The assumption by the general population is that mathematics majors…

The way teachers understand mathematics strongly influences their teaching and what pupils learn. Describes the influence of two variables on preservice teachers' performance: (1) the presence of a formal definition; and (2) previous classroom activities that addressed the concept of the altitude of a triangle. (Contains 30 references.)…

A two year study investigating the state of pre-service teachers' (PTs') (n=224), teachers' (n=18) and students' knowledge (n=123) of Grade 7 geometry (using the van Hiele theory (1986) and acquisition scales of Gutierrez, Jaime & Fortuny (1991)) is reported. Results indicate that both teachers and PTs fail to reach the expected level of…

This document contains the third volume of the proceedings of the 28th Annual Conference of the International Group for the Psychology of Mathematics. Conference presentations are centered around the theme "Inclusion and Diversity". A total of 65 research reports are presented here: (1) A Teacher's Model of Students Algebraic Thinking…

This document contains the fourth volume of the proceedings of the 30th Conference of the International Group for the Psychology of Mathematics Education. Conference presentations are centered around the theme "Mathematics at the Centre." This volume features 59 research reports by presenters with last names beginning between Kun and…

This is a record of the proceedings of the 30th annual conference of the Mathematics Education Research Group of Australasia (MERGA). The theme of the conference is "Mathematics: Essential research, essential practice." The theme draws attention to the importance of developing and maintaining links between research and practice and…