title: The what and how of counting.
authors.affiliation: University of Pennsylvania.
authors.forename: C R
authors.initials: CR
authors.lastname: Gallistel
authors.forename: R
authors.initials: R
authors.lastname: Gelman
mesh_terms: D002657:Child Development; D002675:Child, Preschool; D003210:Concept Formation; D005556:Form Perception; D006801:Humans; D008433:Mathematics; D011340:Problem Solving