FrontMatter -- Preface -- Contents -- Summary -- Part I: Introduction and Research on Learning -- 1: Introduction -- 2 Foundational Mathematics Content -- 3 Cognitive Foundations for Early Mathematics Learning -- 4 Developmental Variation, Sociocultural Influences, and Difficulties in Mathematics -- Part II: Teaching-Learning Paths -- 5 The Teaching-Learning Paths for Number, Relations, and Operations -- 6 The Teaching-Learning Paths for Geometry, Spatial Thinking, and Measurement -- Part III: Contexts for Teaching and Learning -- 7 Standards, Curriculum, Instruction, and Assessment -- 8 The Early Childhood Workforce and Its Professional Development -- Part IV: Future Directions for Policy, Practice, and Research -- 9 Conclusions and Recommendations -- Appendix A: Glossary -- Appendix B: Concepts of Measurement -- Appendix C: Biographical Sketches of Committee Members and Staff -- Index.