The purpose of this study was to describe how an accomplished teacher taught second-grade students to design games that integrated movement and mathematics content. The participants were one physical education teacher, a classroom teacher, and an intact class of 20 second-grade students. Qualitative data were gathered through videotaping of all lessons, descriptions of all 20 children's responses to all lesson segments, and interviews with all participants. In keeping with constructivist principles, the teacher used a progression of tasks and multiple instructional techniques to scaffold the design process allowing children to design games that were meaningful to them. Contrary to descriptions of scaffolding fading across a unit, in this study the scaffolding was a function of the interaction between learners' needs and task content. (Contains 2 tables.)