Abstract
Critical thinking is nowadays considered an important ability, even "hot topic" or "21st century competence". Despite the omnipresence of the concept, it is very difficult to define it.
The purpose of the presentation is to summarize some of the most important factors of critical thinking and methods to stimulate them within mathematical education. This effort is supported by a case study made on the second degree of primary school comparing two ways of presenting word problems and illustrating difficulties of sixth grade pupils to recognize relevant information.
The paper aims to contribute to discovering methods to improve and develop the abilities to evaluate information, recognize relevance and apply available facts.