Conservation of number and continuous quantity in normal, bright, and retarded children.
D000367:Age Factors; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D003071:Cognition; D005260:Female; D006801:Humans; D008607:Intellectual Disability; D007361:Intelligence Tests; D008297:Male; D011582:Psychological Theory