In this paper, we explore a sociological approach to mathematics education and offer a theoretical lens through which we can come to understand mathematics education as part of a wider set of social practices. Many studies of children's experiences in school show that a child's academic success is a product of many factors, some of which are beyond the control and, sometimes, the knowledge of the classroom teacher. We draw on the sociological ideas of Pierre Bourdieu to frame our analysis of the environment in which the pupils learn and the ways in which the practices help to create parallel worlds which are structured quite differently inside and outside the classroom. Specifically, we use Bourdieu's notions of habitus, field and capital. Using two cases, we highlight the subtle and coercive ways in which the practices of the field of mathematics education allow greater or lesser access to the hegemonic knowledge known as school mathematics depending on the cultural backgrounds and dispositions of the learners. We examine the children's mathematical learning trajectories and reflect on how what they achieve in the future will, in all likelihood, be shaped by their social background and how compatible this is with the current educational climate.