Teachers' Mini-Case Studies of Children's Mathematics

This article reports findings from a five-day summer institute conducted with 27 practicing primary-grade teachers. The institute was part of a year-long professional development project that supported teachers' thinking about children's arithmetical understanding. From Quicktime movies that contained excerpts of six children's interviews, pairs of teachers developed mini-cases about the children's arithmetical understanding. At the end of the institute, the teachers presented their mini-case studies to the group. Teachers developed two types of hypotheses: hypotheses about children's thinking and hypotheses about what it means for children to know and do mathematics. After providing examples to clarify the two types of hypotheses, we address the challenges we faced in developing multimedia inquiry-based environments that facilitated teachers' thinking about children's arithmetical thinking. This revised version was published online in August 2006 with corrections to the Cover Date.