1. Mathematics in Action 2. Subitizing: The Neglected Quantifier 3. Discerning a Progression in Conceptions of Magnitude During Children's Construction of Number 4. Spontaneous mathematical focusing tendencies in mathematical development and education 5. Leveraging Relational Learning Mechanisms to Improve Understanding of Place Value 6. The complexity of basic number processing: A commentary from a neurocognitive perspective 7. Understanding Fractions: Integrating Results from Mathematics Education, Cognitive Psychology, and Neuroscience 8. Developing Fractions as Multiplicative Relations: A Model of Cognitive Reorganization 9. Developing a Concept of Multiplication of Fractions: Building on Constructivist and Sociocultural Theory 10. What's Perception got to do with it? Re-framing Foundations for Rational Number Concepts 11. Commentary on Fractions 12. Understanding Negative Numbers 13. Integers as Directed Quantities 14. Cognitive Science Foundations of Integer Understanding and Instruction 15. Commentary on Negative Numbers: Aspects of Epistemology, Cognition, and Instruction 16. Commentary on Negative Numbers: Aspects of Epistemology, Cognition, and Instruction Author index Subject index sakriti opis