- Systematic summaries belong to the end of a didactic situation, because without individual knowledge systematic summaries make no sense.
- New concepts and procedures should prove necessary, e.g. because the means available turn out to be insufficient.
- Formal Operating is developed from basic ideas, so that the meaning of concepts doesn’t get lost.
- Calculus exercises are not an end unto themselves. They have to be designed diverse and meaningful.
- Explanations and proofs shouldn’t focus on absolute strictness, but on understanding and comprehension.