Examining associations between foundational and complex mathematics skills in people with Down syndrome and typically developing children.

Acquiring mathematical competence is essential to independent living. In this study, we investigated the mathematics profile in young people with Down syndrome (DS), and the relations between foundational and more complex mathematics skills. The final sample included 33 participants with DS (58% male, 10.2-31.9 years) and a typically developing (TD) group matched on non-verbal mental age (N = 33, 58% male, 4.5-6.5 years). Participants completed mathematics tasks assessing symbolic number, non-symbolic number, arithmetic, reasoning and geometry. We found that performance was similar on measures of reasoning, non-symbolic number skills and geometry; however, people with DS showed a relative weakness in symbolic number skills and a relative strength in arithmetic. Associations between foundational skills and more complex mathematics also differed somewhat between groups. These differences may reflect the ongoing role of non-symbolic skills for mathematics in people with DS and perhaps the use of more complex strategies in typically developing children.