ABSTRACT
In this paper we look at how students can be supported to reason with a mathematical inscription system. We do so by analyzing several episodes from a classroom design experiment that centered on supporting middle school students’ understanding of proportional relations in the context of measurement. We illustrate how the teacher orchestrated whole-class conversations that built on students’ diverse ways of reasoning and how she used an inscription system to revoice their contributions. We explain that such efforts made it possible for students to start communicating and reasoning mathematically with the inscriptions.
