What does it mean to have mathematical authority? How does it differ from pedagogical authority? We drew upon Goffman's (1981) ideas of author and animator to exemplify modes of mathematical authority that extend beyond the authorship of ideas. Through a series of excerpts from lessons in middle-grades mathematics classrooms, this paper emphasizes…

Dialogue has been characterised as a communicative pattern that supports critical learning in education. Seeking to analyse this relationship, we investigated the interaction between teachers and students in two classes, a Third Grade and a Fifth Grade of São Paulo State public school. During the interaction, we identified a variety of dialogic…

In this article, I examine how a focus on preciseness in the mathematics classroom could affect group activity. The preciseness relates to the ways mathematical concepts, in this case angles are described in discourse between students. In this context, I consider how 'micro-invalidations', can limit students' opportunities to learn in a social and…

Instruments have been used for centuries in mathematical experience and in the teaching tradition as well. One example is cultural instruments inherited from tradition (e.g., rulers, abaci, compasses, curve-drawing devices) that have followed or anticipated the theoretical development of mathematics. In this article, the authors analyze two cases…