Research has shown that the types of tasks assigned to students affect their learning. Various authors have described desirable features of mathematical tasks or of the activity they initiate. Others have suggested task taxonomies that might be used in classifying mathematical tasks. Drawing on this literature, we propose a set of task types that…

Most teachers agree that if a student understands a particular mathematical topic well, he/she will probably be able to do problems correctly. The converse, however, frequently fails: students who do problems correctly sometimes do not actually have robust understandings of the topic in question. In this paper we explore this phenomenon in the…

This article describes an approach for introducing the unit concept in a mathematics content course designed for preservice elementary mathematics teachers. Classroom activities presented in the article emphasize the awareness, flexibility, and importance of the unit concept. Dialogue with selected preservice teachers is included and reveals some…