Number words, in contrast to Arabic digits, are not universals. They depend on the language a person speaks.
Words for small numbers are among the first words learnt. Thus it is important to establish whether language factors influence the association between spoken number words and Arabic digits, and if so, how?
In our longitudinal Numer8ED study we investigated the influence of language on number transcoding by comparing monolingual children from two language backgrounds: English and German.
We chose those two languages because the construction of number words in both languages is broadly similar, with one exception: German is a language with inverted number words [i.e. ‘twenty-five’ in English, but ‘fünf-und-zwanzig’ (‘five-and-twenty’) in German]. This is crucial because number word inversion is one the linguistic factors most likely to affect the efficiency of the mapping of number words to Arabic digits.
This essential manipulation enabled us to test directly whether foundation skills of mathematical development are non-verbal or affected by linguistic factors. This research project, funded by the ESRC, was carried out in collaboration with Professor Karin Landerl and her team at the University of Graz, Austria, who tested German-speaking children in Austria.
A large body of research has documented effects of the linguistic structure of number words on the processing of purely Arabic digits even in adults. This project aimed to dissociate grammatical and lexical linguistic influences on number processing. We compared effects across three languages: Polish, German and English. The project was in collaboration with the Universities of Tuebingen (Professor Nuerk) and Marburg (Professor Domahs), in Germany, and the University of Warsaw (Professor Haman), in Poland.