Part One. 1.1. Young Children's Mathematical Learning: Complexities and Subtleties; H.M. Mansfield. Part Two. 2.1. Constructivism and Activity Theory: A Consideration of Their Similarities and Differences as They Relate to Mathematics Education; P. Cobb, et al. 2.2. A Sociocultural View of the Mathematics Education of Young Children; P. Renshaw. 2.3. Social-Cultural Approaches in Early Childhood Mathematics Education: A Discussion; L.P. Steffe. Part Three. 3.1. The Psychological Nature of Concepts; E. Fischbein. 3.2. What Concepts are and How Concepts are Formed; J. Brun. 3.3. Young Children's Formation of Numerical Concepts: Or 8=9+7; K.C. Irwin. 3.4. Concept Formation Process and an Individual Child's Intelligence; E.G. Gelfman, et al. Part Four. 4.1. Interactions between Children in Mathematics Class: An Example Concerning the Concept of Number; L. Poirier, L. Bacon. 4.2. What is the Difference Between One, Un and Yi?; T. Nunes. 4.3. How do Social Interactions Among Children Contribute to Learning?; A. Reynolds, G. Wheatley. 4.4. Cultural and Social Environmental Hurdles a Tanzanian Child Must Jump in the Acquisition of Mathematics Concepts; V.G.K. Masanja. Part Five. 5.1. Limitations of Iconic and Symbolic Representations of Arithmetical Concepts in Early Grades of Primary School; Z. Semadeni. 5.2. Language Activity, Conceptualization and Problem; N. Bednarz. 5.3. Children Talking Mathematically in Multilingual Classrooms: Issues in the Role of Language; L.L. Khisty.5.4. Use of Language in Elementary Geometry by Students and Textbooks; A. Jaime. Part Six. 6.1. Concept Development in Early Childhood Mathematics: Teachers' Theories and Research; R. Wright. 6.2. Teachers' Beliefs About Concept Formation and Curriculum Decision-Making in Early Mathematics; M. Hughes, et al. 6.3. Classroom Models for Young Children's Mathematical Ideas; T. Yamanoshita, K. Matsushita. 6.4. Joensuu and Mathematical Thinking; G. Malaty. Part Seven. 7.1. Future Research Directions in Young Children's Early Learning of Mathematics; N.A. Pateman.