In this contribution a series of university seminars on mathematical modelling in school will be presented based on a cooperation of mathematics, didactics of mathematics and school. In these seminars modelling examples were carried out in classes of the upper level in secondary schools. First, the theoretical framework of modelling in schools will be discussed, and then the frame concept of the course program. Diverse modelling attempts will be presented in connection with one modelling example, the optimal placement of rescue helicopters. Finally, the last paragraph summarises the evaluation results of the university seminars.