This book reports on the work carried out within the Erasmus+ PLATINUM project by eight European universities from seven countries: the University of Agder, in Kristiansand, Norway—the coordinator of the project—the University of Amsterdam in The Netherlands, Masaryk University and Brno University of Technology in Czech Republic, Leibniz University Hannover in Germany, the Complutense University of Madrid in Spain, Loughborough University in the UK, and Borys Grinchenko Kyiv University in Ukraine. In this 21st century, projects aimed at studying and disseminating inquiry-based approaches in the teaching of STEM disciplines in primary and secondary education have proliferated in Europe, benefiting from the impulse of the publication of the Rocard’s report in 2007.1 However, university mathematics teaching has remained mainly traditional, especially in the first university years, crucial for the students’ orientation and retention.