Units first or tens first: How bilingualism affects two-digit number transcoding?

We investigated the influence of language on transcoding in bilinguals and monolinguals. Bilingual adults who learned math in German (LM+) during primary school and in French during secondary school (LM-) were compared to German and French monolinguals. Participants had to listen to two-digit numbers and had to identify the heard number amongst four visually presented Arabic numbers. To mimic the German vs. the French number word systems, the order of visual appearance of the units and tens of the two-digit numbers was manipulated. Participants also performed a classical transcoding task with simultaneous appearance of the tens and units. Bilinguals were faster to transcode in LM+ than in LM-. Furthermore, they were slower and made more errors when transcoding in LM- compared to monolingual French-speaking participants. We conclude that math acquisition’s language influences simple numerical tasks such as transcoding in adulthood, confirming the critical role of language in numerical cognition.