Summarized are presentations made at a one-day teachers' workshop organized by the Bicultural Socialization Project to discuss the materials to be used in mathematics learning centers in the project classrooms. The first chapter discusses the basic philosophy, whereby pupils are to be encouraged to enjoy the discovery of mathematical relationships through their own activities. Two chapters discuss the mechanics of making assignment cards and of keeping records. Three chapters center on particular themes: pictorial representation (mappings, pictures, charts, set diagrams, tables), number (set description, classification, counting), and linear measurement (length, capacity, weight). A final chapter describes some games which can be used to give practice in number appreciation. Appended is an annotated bibliography on the laboratory approach to the teaching of elementary school mathematics. (MM)