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…

We report on an effort to vet a list of 10 student learning objectives (SLOs) for geometry courses taken by prospective geometry teachers. Members of a faculty online learning community, including mathematicians and mathematics educators who teach college geometry courses taken by prospective secondary teachers developed this list in an effort to…

This article reports and compares results from an interview study of early childhood teachers in the U.S. and Hong Kong, with a focus on the math outcomes that children may gain from play with unit blocks. Teachers were interviewed to obtain their ideas of the benefits of unit block play in three focal areas: geometry, measurement, and numeracy.…

This paper reports on an ongoing project aimed at developing an inter-institutional system of professional support for the improvement of the Geometry for Teachers (GeT) courses that mathematics departments teach to preservice secondary teachers. In alignment with the literature on improvement science (see Bryk et al., 2015; Lewis, 2015), it is…

"Mathematical knowledge for teaching" is a concept indicating the requirement for a specific kind of knowledge required to teach mathematics. Mathematical knowledge for teaching necessitates a more complex structure than what is required to carry out mathematical tasks and the knowledge to do that. The purpose of this study is to realize…

We show how we used a national distribution of responses from 416 practicing teachers to items of a test of mathematical knowledge for teaching geometry to estimate changes in knowledge by a group of 11 practicing teachers who participated in a 2-year practice-based professional development programme. To draw a reliable interpretation of the…

Teachers' content knowledge impacts on what they teach, how they teach and what their students learn. In order to check whether the prospective teachers in a rural South African university know the mathematics content they are expected to teach in the schools, at least at the same depth as their future students expected to attain, the research on…

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…

Building on Shulman's (1986, 1987) construct of Pedagogical Content Knowledge (PCK), Ball and colleagues (Ball, Thames & Phelps, 2008) created a model of mathematical knowledge for teaching that differentiates between subject matter knowledge and PCK. The model categorises different types of knowledge within these two domains. In this research…

This paper addresses the continuing need for mathematics teachers to enrich their mathematical knowledge beyond the school curriculum, in order to effectively engage students in creative and imaginative thinking, particularly, but not exclusively, students who show exceptional promise. The author, a retired university professor, works staff and…

These proceedings are a written record of the research presented at the 41st annual meeting of the North American Chapter of the International Group for the Psychology of Mathematics Education (PME-NA) held in St. Louis, Missouri, November 14-17, 2019. This year's conference theme is "...against a new horizon." The papers comprise 67…

This study investigated the ways in which four middle grades teachers developed mathematical knowledge for teaching (MKT) geometry as they implemented dynamic geometry software in their classrooms with the assistance of a coach. Teachers developed various components of MKT by observing coaches teach, by dynamic discourse with students, which is…

This study investigated the relationship between prospective secondary mathematics teachers' perspectives and their mathematical knowledge for teaching in action. Data from two prospective teachers' practice-teachings, one in geometry and one in algebra, their lesson plans and self-reflections were analyzed with Teacher Perspectives and Knowledge…

These Proceedings are a written record of the research presented at the 40th Annual Meeting of the North American Chapter of the International Group for the Psychology of Mathematics Education (PME-NA) held in Greenville, South Carolina, November 15-18, 2018. The theme of the conference is "Looking Back, Looking Ahead: Celebrating 40…

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…