Mathematics is a central part of school curricula around the world. There has been much interest in linguistic aspects of the teaching and learning of mathematics, both from mathematics educators and from applied linguists. This short paper introduces a set of five articles exploring the intersection between these two communities. The articles all discuss two texts: an extract from the guidance issued to primary school mathematics teachers in the UK; and an extract from a primary school mathematics lesson. This paper begins by summarising some of the research on language in the mathematics classroom, before introducing the two texts.