1. Introduction: How the Study of Neurobiological and Genetic Factors can Enhance our Understanding of Mathematical Cognitive Development Part I: Neural Substrates 2. Number Symbols in the Brain 3. Neural and Behavioral Signatures of Core Numerical Abilities and Early Symbolic Number Development 4. A Neurodevelopmental Perspective on the Role of Memory Systems in Children's Math Learning 5. Finger Representation and Finger-Based Strategies in the Acquisition of Number Meaning and Arithmetic 6. Neurocognitive Architectures and the Nonsymbolic Foundations of Fractions Understanding 7. Developmental Dyscalculia and the Brain 8. Neurocognitive Components of Mathematical Skills and Dyscalculia 9. Individual Differences in Arithmetic Fact Retrieval 10. Transcranial Electrical Stimulation and the Enhancement of Numerical Cognition Part II: Genetic Influences 11. Individual Differences in Mathematics Ability: A Behavioral Genetic Approach 12. Genetic Syndromes as Model Pathways to Mathematical Learning Difficulties sakriti opis