The notion of mathematical modelling is not new; however, with the development and access to cheap, powerful calculator and computer technologies, students in schools are able to engage with sophisticated mathematical contexts that have relevance outside of the classroom, a view of mathematics not commonly held by students. From one of the workshops of modelling challenge, we analyse a conversation between a group of students as a way of providing a meaningful example of the types of conversations students have while they engage in thinking about and doing mathematical modelling.