Given two vectors u and v, their cross product u × v is a vector perpendicular to u and v. The motivation for this property, however, is never addressed. Here we show that the existence of the cross and dot products and the perpendicularity property follow from the concept of linear combination, which does not involve products of vectors. For our…

Two content topics will be described. One deals with geometric measurement: length, area, and volume. These are important topics and they have not been learned very well. In particular, what types of relations can one consider when dealing with these three aspects of geometric measurement? The second topic is fractions, and different views of what…

The incorporation of subject-specific technologies in teaching and learning mathematics has been extensively investigated in different areas outside Uganda. The benefits are extensive, although the adoption of these technologies has been threatened by teachers needing help to apply them effectively for instruction. While this alone would aptly…

Despite significant research exploring students' quantitative reasoning, few studies have explored the semiotic processes that mediate its development. In this report, we present a case study to show how one student constructed a semiotic chain for a quantity as he worked with a mathematical task. Importantly, we connect frameworks for…

This article presents a didactic situation focused on geometric reasoning using 3D GeoGebra, using the concepts Theory of Didactical Situations (TDS). The objective of this work is to bring a didactic proposal for the teaching of Spatial Geometry, working with the students' geometric perception, oriented and elaborated based on the dialectic of…

Geometric thinking affects success in learning geometry. Geometry is studied from elementary school to university level. Therefore, in higher education and basic education, it is necessary to carry out a systematic review in order to obtain tips for improving geometric thinking skills. A systematic review of geometric thinking was done in this…

When geometry teaching lacks elements of flexibility, inclusivity and accessibility, it is often difficult for learners to follow and understand what they are being taught. In line with this, this paper reports on the application of universal design for instruction (UDI) to guide flexible and accessible teaching of geometry to maximise learning.…

Art is a special tool for mathematics education. Many artists have used mathematics and geometry in their artworks. This study aims to examine M.C. Escher's drawings with creative drama in the light of transformation geometry. In this study, the explanatory sequential was chosen from the mixed-method designs. Quantitative data of the study were…

To fulfill the Standards for Mathematical Practice (National Governors Association Center for Best Practices & Council of Chief State School Officers [NGA Center & CCSSO], 2010), it is important for teachers to empower students to critique, revise, and expand their ideas as they solve problems. However, students often face challenges such…

Mathematics curricula are often the primary resource used in the teaching and learning of mathematics--in particular, they represent mathematical knowledge for teachers and students. Yet, there seems to be a discrepancy between the curricular materials written for teachers and students (e.g., more variety in the semiotic choices in text provided…

Objectives: This study aims to investigate the feasibility and efficacy of competency-based course (Conceptual Geometry). In addition, this paper presents the procedures of developing competency-based course which include mapping out competencies of the course, developing a set of assessment instruments (e.g., diagonal, pre-and post-unit…

This paper reports on a study conducted within VIDEO-LM (Viewing, Investigating and Discussing Environments of Learning Mathematics), a video-based professional development project for secondary mathematics teachers that aims to enhance reflection on practice. The study explored VIDEO-LM sessions where Israeli teachers watched an 8th grade…

We live in the challenging times of the 21st-century with the increased need for humans to possess specific skills that will help them to be successful in this era. This means that education should in learners, develop these skills effectively. Different global countries have begun to recognize the significance of multiple solutions tasks in the…

This study examined the effect of implementing personal devices into a fifth-grade mathematics classroom. Thirty-eight fifth graders participated in this eight-week project with a focus on six students to track their growth. During this study, students engaged in technology-based stations that pertained to our geometry unit and coordinate unit.…

This paper initiates a discussion around the potential of Dynamic Measurement, an alternative approach to geometric measurement that focuses on how space is generated, and thus measured by the lower-dimensional objects that define it. I use data from a series of design experiments with fourth-grade students to illustrate some forms of reasoning…