Representation lies at the heart of doing mathematics. It is the activity of creating and using mathematical symbols, signs, and diagrams. NCTM (2000) advocates that students be fluent users of representations and that instruction should support students in learning to navigate mathematical concepts and problem solving through the use of a variety of representations.
Despina A. Stylianou, email@example.com, an associate professor of mathematics education at the City College of New York, is interested in the development of students' mathematical practices across the grades. She wishes to acknowledge the work of Kara Imm and Rachel Lambert, graduate research assistants for the project, who led the teaching experiment and participated in the data analysis. She is also grateful to Debra Johanning for her thoughtful comments, and to the school, teachers, and students for their willingness to allow them to be part of their mathematical journeys.