The distinction of problems according to their closeness to reality is not meant to be a valuation.
All three types of problems are important for learning mathematics and for students’
mathematical competence. Which problems ought to be used in class depends on which
mathematical competencies are to be acquired during classroom instruction. As learning is often situated and a transfer of knowledge between the various areas of knowledge can only be attained to a limited degree (Greeno, 1989), it makes sense when developing, e.g., the competence “symbolic/formal/technical work” (cf. Leiss & Blum, 2006) to work on related intra-mathematical problems.