This book demonstrates how K-2 students deepen their mathematical ideas when encouraged to represent and communicate their thinking. Numerous vignettes from actual classrooms and reflective comments from teachers provide a model for how show and tell can enhance classroom teaching and improve children's learning. Examples of students' work and practical advice such as how to encourage the participation of all learners, how to enhance student discussions, and how to decide when to intervene in the sense-making process are provided to help teachers become successful. (KHR)