Vygotsky's work on the individual/social relation provides theoretical tools for interpreting the origins of thinking and learning. Drawing on Vygotsky's ideas and data from one classroom, categories of practice relating to teaching and learning were developed in order to identify themes for an exploration of mathematical development within the classroom. These themes informed a qualitative investigation of the process that, in Vygotskian understanding, characterises the emergence of mathematical development. The investigation endeavoured to examine that relation with respect to a teacher's activities and her students' activities in the mathematics classroom.