How does the election of the German Bundestag work? How are seats in Swiss cantonal parliaments calculated? Is it even possible to convert voting numbers fairly to mandates? Seat allocation methods and their most important formal characteristics are the subject of this compact course, which has been tried and tested at the University of Augsburg. Proportional voting systems and their methods of converting the number of votes into mandates at the end of a democratic election are dealt with in detail and vividly here. Numerous examples with the latest election results ensure realism. Constitutional law and political science claims, which must be met by seat allocation methods, are also explained and emphasize the interdisciplinary character of the question.