ABSTRACT
Investigations in Number, Data, and Space is designed to provide a coherent, comprehensive curriculum for Grades K-5 that allows all students to explore important mathematical ideas. Each of the four content strands (number, data, geometry, and the mathematics of change) is developed from kindergarten through fifth grade. Some data units emphasize categorical data, in which the emphasis is on the process of classification and description; others emphasize numerical data, in which the emphasis is on examining variability, the shape of the data set, and indicators of center. Classroom observations showed that instruction in the Investigations classrooms focused on students sharing their numerical strategies. Instruction in the mixed classrooms consisted primarily of teacher-directed instruction. Besides being more accurate with respect to solving complex problems, students in the Investigations groups showed qualitatively different ways of thinking about the operations than students in other groups.
