Abstract
IDidactical content knowledge is a concept discussed frequently in recent didactical literature, especially in the context of improvement of teacher education. From the wide research area the here presented study focuses on one of the twenty parameters that characterise a teacher's educational style.
The perspective on teacher's didactical competences is narrowed to an important area of the teacher's work with their pupil's mistake. Four didactical mistakes are described and illustrated on examples from written tests of five student teachers.
The study tries to uncover the causes and the consequences of the mistakes and to find such re-educational tool that will enable the teacher to overcome their mistakes.