Arithmetic performance in children with typical and impaired literacy skills

The present study investigates the overlap between arithmetic and literacy, by examining arithmetic performance in children with combined reading and spelling deficits, isolated reading or spelling deficits and age-appropriate (typically developing) reading and spelling skills. We also examine whether controlling for literacy predictors (RAN, phonological awareness) explains group differences in arithmetic performance.

One hundred sixty-one elementary school children from Grades 2-5 participated in our study. We classified children based on their reading fluency and spelling performance. Children scoring below the 20^th percentile were classified as impaired. In addition to the reading and spelling tasks, children completed a timed arithmetic task, as well as a verbal phonological awareness and a computerized RAN task with letters.

Children with combined reading and spelling deficits demonstrated poorer arithmetic performance than children with isolated spelling deficit and typically developing peers. However, these differences disappeared after controlling for phonological awareness and RAN alone or together. Bayesian analyses supported the null model when linguistic predictors were included.

The results confirm the overlap between literacy and numeracy difficulties, suggesting that children with combined reading and spelling deficits are at greater risk of also having an arithmetic difficulty than children with isolated literacy problems. Underlying language skills, particularly RAN and phonological awareness, account for the overlapping deficits.