Equals in the wild: How mathematical equality is talked about in lessons

Abstract

Equality is a nuanced concept in mathematics, and the equals sign is used and interpreted in different ways. During professional development in language-responsive teaching, a group of teachers discussed the use of ‘equals’ in algebra lessons. This article considers how three of these teachers went on to invoke equality in their classroom interactions when teaching other topics. The cases observed suggest constructive resonances between conceptions of ‘equals’ and geometric relationships, and include examples of teachers balancing precision with fluency. We argue that attention to language in one mathematical topic may extend helpfully to other topics, but this is not automatic