This monograph chronicles a field-based investigation of children's learning in a second grade mathematics classroom over the course of a school year. The interrelated aspects of the processes by which children learn mathematics with meaning are illustrated here. The investigation was expanded to include a sociological analysis in an attempt to understand the relation between individual mathematical constructions and classroom social interactions. Data include clinical interviews of individual children's mathematical constructions and video recordings of classroom lessons. Microanalyses of specific episodes from the classroom are included in order to illustrate the theoretical constructs that evolved over the course of the investigation. The material is organized in three parts that relate to multiple perspectives of learning mathematics; culture, community, and the meaning of mathematics; and commentary on issues and reform in mathematics education. Contains 164 references. (DDR)