The overarching topic of the 3-year project is the automatic nature of symbolic numbers’ representation (single and multiple digit numbers). Symbolic number representation and manipulation is a key of successful mathematical learning. Many behavioral and neuroimaging evidence highlighted that it is not possible to ignore the numerical magnitude when looking at number symbols, at least for adults. Moreover, language is crucial for math learning and shapes numerical representations. We will develop novel frequency-tagging EEG paradigms to assess the automatic representation and access to the numerical magnitude information conveyed by number symbols. Our paradigms are language-free, making them ideal candidates to investigate number representations in multilingual environments. The first part of the project will consist in assessing automatic access and representation of magnitude information from number symbols in adults with different language profiles: multilinguals vs. monolinguals. The second part of the project aims at tracking typical and atypical development of numerical representations in multilingual children. We will apply the EEG paradigms of the first part of the project to groups of multilingual children with or without mathematical learning disabilities, with or without associated language learning disabilities. Results will be matched with similar groups of monolingual children. In the third part of the project, we will analyze neural synchronization among the EEG recordings to measure brain connectivity patterns and to compare brain networks properties in the different populations. The project will bring a new understanding of multilingual numerical cognition and provide potential biomarkers of mathematical learning disabilities in multilingual settings.