Michele M. M. Mazzocco, PhD; Research Scientist; Director, Math Skills Development Project, Kennedy Krieger Institute; Professor of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine; author of “Pathways to mathematical difficulties and disabilities” (2009, Developmental Disabilities Research Reviews); co-editor of Why is Math So Hard for Some Children: The Nature and Origins of Mathematics Learning Difficulties and Disabilities (2007)