I draw attention to the distinction between reductionist views of "language" and the rich and complex ways in which we might approach language as social practice and suggest the latter view is evident in the set of papers collected here. Socially oriented linguists, including those in New Literacy Studies (NLS), look beyond reductionism, to consider more complex "social" features of language and literacy. This perspective includes: viewing language and literacy as a process rather than as a fixed entity and as a resource rather than as a set of rules; exploring the role of language and literacy in implementing social agendas and in establishing relations between participants, such as their role in establishing and challenging power relations; and the relation of language and literacy to other means of communication and meaning making, such as visual, gestural, and iconic, that are usually woven in with language use. I consider how appropriate it might be to apply aspects of these approaches and in particular of the "academic literacies" approach linked to them, to what we might term the "academic numeracies" at play in the texts under consideration. These perspectives entail an assumption that participants deploy "hidden knowledge" of the features of language, literacy and numeracy in order to accomplish their social ends and that the task of the researcher is to bring into view and to unpack these hidden dimensions. Identifying such "hidden" features of classroom discourse can, then, help teachers and policy makers recognise important communicative features of classroom interaction that are missed when the focus is on "correctness", "definition", formal features of language and "lack of ambiguity", as in some curriculum documents and approaches.