Daniel B. Berch is Associate Chief, Child Development and Behavior Branch, National Institute of Child Health and Human Development, National Institutes of Health, in Bethesda, Maryland. Michele M.M. Mazzocco is Associate Professor of Psychiatry, Johns Hopkins School of Medicine; Associate Professor of Population and Family Health Sciences, Johns Hopkins Bloomberg School of Public Health; and Director, Math Skills Development Project, Kennedy Krieger West Campus, in Baltimore, Maryland.

• Characterizing Learning Disabilities in Mathematics; Historical Overview of the Field; Classification and Definitional Issues; Prevalence of Developmental Discalculia; Cognitive and Information Processing Features; Fundemental Information-Processing Deficits; Strategy Use, Long-Term Memory, and Working Memory Capacity; Do Words Count? Connections between Mathematics and Reading Difficulties; Fraction Skills and Proportional Reasoning; Neuropsychological Factors; Specific Language Impairment and Mathematical Disabilities; Neurodevelopmental Disorders (Turner, Fragile X, Williams); Mathematical Disabilities in Congenital and Acquired Neurodevelopmental Disorders; Neuropsychological Case Studies on Arithmetic Processing; Neurobiological and Genetic Substrates; Neuroanatomical Features of Mathematical Processing; Quantitative Genetics and Mathematical Abilities/Disabilities; Additional Influences on Math Disability; Is Math Anxiety a Mathematics Learning Disability?; Influences of Gender, Ethnicity, and Motivation on Mathematics Performance; Instructional Interventions; Early Intervention for Children at Risk of Developing Math Disabilities; Mathematical Problem Solving: Instructional Intervention; Quantitative Literacy and Developmental Dyscalculia.