We present results from a classroom-based intervention designed to help a class of grade 10 students (14-15 years old) learn proof while studying trigonometry in a dynamic geometry software environment. We analysed some students' solutions to conjecture-and-proof problems that let them gain experience in stating conjectures and developing proofs.…

In this article, we report how a geometric task based on the ACODESA methodology (collaborative learning, scientific debate and self-reflection) promotes the reformulation of the students' validations and allows revealing the students' aims in each of the stages of the methodology. To do so, we present the case of a team and, particularly, one of…

This research study was conducted to identify core practices of enacting effective mathematics pedagogy with GeoGebra, a software application for teaching and learning mathematics. Eleven Ghanaian in-service mathematics teachers were engaged in a twelve-month professional development programme where they developed GeoGebra-based mathematics…

The aim of this study is to observe the effect of Education and Informatics Net (EIN) supported math teaching on students' success in geometry teaching 5th grade level and to observe students' comments on EIN. This study was conducted in the 2nd term of 2018-2019 school year. Both qualitative and quantitative research methods were implemented.…

For many decades, the amount of geometry curriculum worldwide has been cut, mathematics curricula have lacked diversity of geometrical phenomena, and geometry teaching has been reduced to a somewhat eclectic mix of activities. Recently, new trends have begun to counteract these tendencies by framing new curricula around fundamental ideas. The…

The study reported in this article addresses the question of how professional development can increase teacher noticing of student thinking over time. The data come from five teachers' participation in a two-year professional development intervention that combined lesson study, video clubs, and animation discussions. The analysis focuses on…

Thomas Kuhn (1962/2012) introduced the term "paradigm shift" to the scientific literature to describe how knowledge in science develops. The aims of this article are to identify paradigm shifts, or revolutions, that have occurred in mathematics, and to discuss their relevance to teaching mathematics in schools. The authors argue that…

The purpose of the present paper is to study the positions and emotions of grade 7 students who work with technology to learn geometry. This consideration of students' emotions is socially based, which makes it necessary to use a socially-based theoretical framework in order to study them. One such theory is the discursive analysis framework…

This action research study examined the effects of review games using Kahoot! on students' quiz scores as well as student engagement. The study was conducted in a high school geometry classroom at Tiyan High School (THS) in Barrigada, Guam. This study consisted of a sample size of 42 students in the 10th through the 12th grade. The data collected…

There is a great deal of overlap between the set of practices collected under the term "computational thinking" and the mathematical habits of mind that are the focus of much mathematics instruction. Despite this overlap, the links between these two desirable educational outcomes are rarely made explicit, either in classrooms or in the…

In this study, we investigate sixth, seventh, and eighth grade students' achievement in nonlinear (quadratic or cubic) proportional problems regarding length, area, and volume of enlarged figures. In addition, we examine students' solution strategies for the problems and obstacles that prevent students from answering the problems correctly by…

When the focus of instruction is on learning to use mathematical tools--such as a ruler or a calculator--as a procedure, students tend not to incorporate their own mathematical reasoning. This unreflective use of tools hinders students' questioning of the reasonableness of their answers. This article describes how children expressed their…

In this paper we probe prospective mathematics teachers' thinking as displayed in their solutions to a geometry content knowledge-based task. Geometry content knowledge is examined in terms of connections made by these prospective teachers between the geometric configurations and the geometric principles established through visualization and…

This study aims to analyze how the Mathematics Teacher Candidates (MTCs) define the "prism" and "pyramid" concepts in geometry. The research was carried out in 2017-2018 academic year with 92 MTCs. This test consists of 3 open-ended questions that MTCs can answer conceptually. The first openended question was as "Define a…

In this article the authors described their exploration of a particular design element they labeled "video in the middle." As part of the video in the middle design, the viewing of carefully selected video clips from teachers' classrooms is sandwiched between pre- and postviewing activities that are expected to support teachers'…