Demanding transfer processes between reality and mathematics are the core of modelling
activities (Blum et al., 2007; Pollak, 1979). One of the process models to describe
modelling activities is the modelling cycle proposed by Blum and Leiss (2007). In an
idealised form, the solution process for a modelling problem can be characterised by a
seven-step sequence of activities: (1) understanding the problem and constructing an
individual “situation model”; (2) simplifying and structuring the situation model and thus constructing a “real model”; (3) mathematising, i.e. translating the real model into a mathematical model; (4) applying mathematical procedures in order to derive a result; (5) interpreting this mathematical result with regard to reality and thus attaining a real result;(6) validating this result with reference to the original situation; if the result is unsatisfactory, the process may start again with step 2; (7) exposing the whole solution process.