Linguistic precursors of sixth-grade geometric and fraction skills in children with and without Developmental Language Disorder

Previous research has shown that foundational linguistic skills (i.e., phonological awareness and grammatical ability) indirectly (through arithmetic skills) predict growth from fifth-to sixth-grade geometric and fraction skills. Our study aimed to investigate the linguistic precursors of sixth-grade geometric and fraction skills in children with and without DLD, while examining potential (cognitive) strengths within the DLD group that may partly compensate for learning geometry and fractions, at both the group and individual level. Participants were 46 children with DLD and 122 typically developing peers from 9 to 11 years of age. Classroom and individual measures were administered in both grade 4 and grade 6. At the group level, results showed children with DLD to score below their peers on arithmetic, geometric, and fraction skills. Furthermore, indirect effects of phonological awareness and naming speed, via arithmetic skills, on geometric and fraction skills were found to be equally strong for both groups. In addition, similar strengths for both groups were found for nonverbal intelligence, academic vocabulary, and verbal reasoning in directly predicting the scores in geometric and fraction skills. Finally, at the individual level, a strength in verbal reasoning was found to partly compensate the delays in mathematics in children with DLD. The educational needs of children with and without DLD in mathematics learning might be more quantitative in nature than that they are qualitative. In addition, identifying individual strengths should be integrated into standardized test batteries and treatment approaches. • We examine linguistic precursors of sixth-grade geometric and fraction skills. • Children with DLD perform lower on tasks of geometry and fractions. • Children with and without DLD equally rely on linguistic skills in learning math. • Verbal reasoning strengths in DLD may partly compensate geometry and fractions. • Identification of protective factors in DLD require individual level statistics.