1. Hector Research Institute of Education Sciences and Psychology, University of Tübingen, Tübingen, Germany
2. LEAD Graduate School & Research Network, University of Tübingen, Tübingen, Germany
3. Centre for Mathematical Cognition, School of Science, Loughborough University, Loughborough, UK
4. Leibniz-Institut für Wissensmedien, Tübingen, Germany
5. Department of Psychology, University of Tübingen, Tübingen, Germany