General and Mathematical Language Contribute to Numerical Performance Differences in Linguistically Diverse Third Graders

General and mathematical language are important predictors of mathematical abilities. Both factors are particularly important in multilingual education contexts, such as Luxembourg, where many students do not speak the language of math instruction at home, which may thus impact their performance in mathematical tests. The present study investigated how general and mathematical language contribute to individual differences in third graders attending schools in Luxembourg (N = 537, 49% girls). All children performed a series of newly developed numerical and arithmetic tasks. We also devised and administered a receptive vocabulary measure with 45 general and 16 mathematical language items. Further measures included demographics and rapid automatized naming (RAN).
In general, it appeared that children who were speaking the language of instruction at home (L1 learners; 43%) scored overall higher than their peers speaking other languages at home (L2 learners; 57%). More fine-grained analyses revealed that these effects only concerned the tasks assessing basic numerical skills. Stepwise regression analyses controlling for sex, age, socioeconomic status and performance in RAN indicated that performances of L1 versus L2 learners no longer differed when taking general and mathematical language levels into account. Mediation analyses confirmed that general and mathematical language both significantly mediated the relationship between the effect of language background and basic numerical task performance.
These results confirm and extend previous studies reporting that lower language proficiency contributes to underachievement of L2 learners. In addition, they highlight the specific contribution of mathematical language to numerical performance of elementary-school children with diverse language backgrounds, extending findings in preschool children. Our findings underscore the importance of considering general and mathematical language skills when assessing math performance in linguistically diverse children. Vocabulary training and active use of mathematical language might help foster math abilities and reduce achievement gaps related to language backgrounds.