Recognizing identity not only as an important educational outcome but also as being inter-related to students' knowledge and practice, this paper explores an affordance of proof scripts; exploring students' identities. Specifically, drawing on data from teaching experiments and the construct of perceptual ambiguity, this paper presents an analysis…

We present a synthesis of the Onto-semiotic Approach (OSA) theoretical system to mathematical knowledge and instruction, while highlighting the problems, principles and research methods that are addressed in this approach and considering the didactics of mathematics as a scientific and technological discipline. We suggest that Didactics should…

An important issue in mathematics education in many countries has long been how to make use of students' daily life mathematics (informal mathematics) in teaching mathematics at school (formal mathematics). This communication proposes an alternative framework of mathematics education that bridges informal and formal mathematics using…

We aim to open up discussion about the intertwined roles of teachers and tasks that involve students communicating about mathematics when working in groups. Over many years we have observed, researched and ourselves have taught students working on mathematics in groups and find that it is often easier to pay attention to the forms of communication…

How do students cope with and make sense of polysemy in mathematics? Zazkis (1998) tackled these questions in the case of 'divisor' and 'quotient'. When requested to determine the quotient in the division of 12 by 5, some of her pre-service teachers operated in the domain of integers and argued for 2, while others adhered to rational numbers and…

Many predominantly English-speaking countries have problems understanding the notion of "didactics" as it is used in many European and other countries. The term appears almost exclusively in the UK as a description of a form of teaching which in recent decades has been seen pejoratively. Didactic teaching is taken to mean teaching with…

This paper focuses on the design of tasks that situate teachers in the work of mathematics teaching. We examine a simple, yet fundamental feature of pedagogical content knowledge tasks: the extent to which pedagogical warrants are necessitated by the pedagogical context. We argue that this feature has implications for the design of tasks, as well…

The literature concerning students' understanding of the equal sign has focused narrowly within the context of formal mathematics. Researchers have put forth a hierarchy of conceptions of the equal sign with only the top level regarded as correct. Meanwhile, we find that the equal sign is used widely and in a variety of ways in advertising and…

When deciding what constitutes students' "on task" or "off task" mathematical communication, teachers and researchers are also making judgements about what is, and what is not, mathematics. In this paper, we question our ability to separate the mathematical from the nonmathematical. We explore intersecting storylines in Grade…

This article suggests a tool for analysing diagrams in mathematical texts. The starting point for this tool is Halliday's Systemic Functional Grammar (SFG), which considered language as a social practice. Kress and Van Leeuwen (2006) applied Halliday's SFG to images, suggesting a grammar for reading images. Morgan (1996) adopted Halliday's SFG and…

A poetic structure occurs when a speaker's comment repeats some of the syntax and words of a previous comment. During a collaborative algebra task, a student explained a property five times over a few minutes, in slightly different ways. He consistently used poetic structures that were marked elaborately through discursive modes such as pause,…

This article brings an enactivist perspective to the question of what can be said about mathematics teacher learning from observations of talk (including transcript, interview and questionnaire data). From an enactivist stance, doing and knowing are equivalent and learning is a change in knowing/doing. Through an analysis of transcript data, four…

Our aim is to discuss some choices of communicational artifacts made by Maxakali Brazilian Indigenous students to register and operate with numbers in a mathematics education course, and how these choices reflect in the ongoing classroom activity. We rely on Activity Theory to analyze an activity involving them and discuss how the choice of…

Based on input from several scholars, Gascón and Nicolás (2017) attempted "to start a dialogue aimed at laying the foundations for a better understanding and a scientific cooperation between different theories in Didactics." Consistent with that goal, I examine uninterrogated assumptions that shaped their analysis. I assert that such…

Supporting students developing understandings of function has been a notoriously elusive task in mathematics education. We present Thompson and Carlson's (2017) description of a covariational meaning of function and provide an example of a student who maintains meanings compatible with this description. We use this student's activity to illustrate…