Is grade 7 too late to start with bilingual mathematics courses? an intervention study

Bilingual mathematics courses have proven to be beneficial for multilingual learners because activating home languages can facilitate the access to mathematics, especially in the early years of schooling. But does this argument also apply to older multilingual students who have not received an opportunity to develop their home languages in the academic and mathematical technical register? Or do language barriers in these registers hinder the mathematical learning process? The presented intervention study explores the realizability of bilingual mathematics courses in Grade 7, for German-Turkish speaking immigrant students in German schools without prior formal mathematics education in their Turkish home language. The randomized control trial shows that even in the short time (5 x 90min.), students can equally profit from bilingual learning opportunities as from monolingual German learning opportunities, although some time and effort is required for overcoming initial barriers in the home language.