Training Quantity-Number Competencies in Students With Intellectual Disabilities

Literature reviews offer evidence for using systematic instruction to teach students with intellectual disabilities in mathematics. A new approach in teaching mathematical skills is to provide quantity-number competencies (QNC). However, this approach has not yet been examined in people with intellectual disabilities. The objective of this study was to evaluate the effects of a QNC training based on the developmental model by Krajewski (2008) in students with intellectual disabilities. Based on their cognitive and mathematical abilities, 25 children with intellectual disabilities were assigned to one of two experimental conditions. The training group received a QNC training, whereas the control group received a language skills training. The posttest findings indicate that the gains in mathematics competence in the QNC training group were substantially larger than in the control condition. However, the QNC training group could not keep up their advancement of competency until to the follow-up conducted 3 months afterwards.