The dominant paradigm within which research, testing, and theorising on the meaning of understanding are framed is a psychological one, which is generally interpreted as the study of the mind Inevitably, therefore, it focuses on the individual. Recent ideas in mathematics education, drawn from discourse analysis (e.g. Pimm, 1990, this volume; Walkerdine, 1988, 1989) and social practice theory (e.g. Evans and Harris, 1991; Dowling, 1991), indicate that a consideration of social interactions does more than merely shed light on the understanding of the individual. Their critique suggests that understanding cannot be approached except through a focus on the social. The chapters in this book all pick up on a socio-cultural focus for the mathematics classroom and elaborate it from their own particular interests. In this chapter I will offer an interpretation of this shift in focus towards the socio-cultural, and suggest some activities for the mathematics classroom that may be seen to be fruitful in this context.