Summary: To teach mathematical modelling to prospective upper secondary teachers is not trivial. Since the Swedish curriculum from 2011 recommends mathematical modelling for all students who study major courses in mathematics in upper secondary school, only the very young students in the teacher training programs have some experience of mathematical modelling. Up until now, there has not been adequate material for students who are in upper secondary school or for student what want to be mathematics teachers in upper secondary school. With a recently published book and with adequate technical support, prospective teachers of today can be taught and learn mathematical modelling. When given the opportunity, most of them quite unexpectedly selected mathematical modelling examples to explain social science phenomena.