title: Knowledge of mathematical equivalence in children with specific language impairment: insights from gesture and speech.
abstract: OBJECTIVE
  This study investigated understanding of mathematical equivalence in children with and without specific language impairment (SLI).
  
  
  METHODS
  A total of 34 children (ages 8;1 [years;months] to 11;7), including 9 with expressive SLI (E-SLI), 8 with expressive and receptive SLI (ER-SLI), and 17 age-matched typically developing (TD) children completed addition and mathematical equivalence problems. The problem-solving strategies revealed in solutions and in gestural and verbal explanations were coded.
  
  
  RESULTS
  The children with SLI were less accurate than their TD peers in solving addition and equivalence problems. None of the children in the ER-SLI group solved the equivalence problems correctly; however, the number of children who solved any of the equivalence problems correctly did not differ in the E-SLI and CA groups. Children in the ER-SLI group tended to express incorrect strategies for solving the equivalence problems in both gesture and speech, whereas children in the E-SLI group often expressed correct strategies in gestures, but incorrect strategies in speech.
  
  
  CONCLUSIONS
  Children with SLI showed delays in their knowledge of mathematical equivalence. Children with ER-SLI displayed greater delays than children with E-SLI. Children with E-SLI sometimes expressed more advanced knowledge in gestures, suggesting that their knowledge is represented in a nonverbal format.
authors.affiliation: Pennsylvania State University, Communication Sciences and Disorders, 105 Moore Building, University Park, PA 16802, USA. ezm3@psu.edu
authors.forename: Elina
authors.initials: E
authors.lastname: Mainela-Arnold
authors.forename: Martha W
authors.initials: MW
authors.lastname: Alibali
authors.forename: Kristin
authors.initials: K
authors.lastname: Ryan
authors.forename: Julia L
authors.initials: JL
authors.lastname: Evans
mesh_terms: D002648:Child; D003210:Concept Formation; D004521:Educational Measurement; D005260:Female; D005868:Gestures; D006801:Humans; D007805:Language Development Disorders / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D007859:Learning Disabilities / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D008297:Male; D008433:Mathematics; D010379:Peer Group; D011340:Problem Solving; D012016:Reference Values; D012572:School Health Services; D014705:Verbal Behavior