Contents -- 1 Toward Number Theory as a Conceptual Field -- 2 Coming to Terms with Division: Preservice Teachers' Understanding -- 3 Conceptions of Divisibility: Success and Understanding -- 4 Language of Number Theory: Metaphor and Rigor -- 5 Understanding Elementary Number Theory at the Undergraduate Level: A Semiotic Approach -- 6 Integrating Content and Process in Classroom Mathematics -- 7 Patterns of Thought and Prime Factorization -- 8 What Do Students Do with Conjectures? Preservice Teachers' Generalizations on a Number Theory Task -- 9 Generic Proofs in Number Theory -- 10 The Development of Mathematical Induction as a Proof Scheme: A Model for DNR-Based Instruction -- 11 Reflections on Mathematics Education Research Questions in Elementary Number Theory -- Author Index -- Subject Index -- About the Contributors.