Sixty-twelve = Seventy-two? A cross-linguistic comparison of children's number transcoding.

We compared French- and English-speaking fifth-grade (10-year-old) children's performance in number transcoding. Whereas English two-digit number names follow the decimal structure (base 10), the structure of French two-digit number words over 60 follow a vigesimal structure (base 20). Children undertook two number transcoding tasks. While children were generally successful at the tasks, English-speaking children significantly outperformed French-speaking children for numbers following a vigesimal structure in French compared to a decimal structure in English (i.e., numbers >60). Our findings show that verbal number name structures influence children's performance in numerical tasks, even though fifth-grade children have well passed the initial stage of acquiring transcoding skills for two-digit numbers. These findings highlight the importance of language specificities in children's number transcoding. Statement of contribution What is already known? Previous research reports that language influences number processing in young children. Number transcoding performances can be conditioned by the linguistic structure of number words. What does this study add? Our results show how the structure of French vigesimal number words impacts number transcoding. They demonstrate that these language influences also affect children who already master basic number competencies.