Illustrates the multiple strategies used by second graders to solve a problem with three addends and how their teacher tries to map their thinking into the system of mathematical notation. Describes the American Federation of Teachers' Thinking Mathematics program that the teacher uses. (MKR)

This brief report from the Indigenous Mathematics Project focuses on the way in which numerical reasoning is changing in the Oksapmin community of Papua New Guinea as a function of participation in new social institutions: economic exchange with currency and enrollment in school. Each of these new institutions means that arithmetic problems are…