Abstract
Zero is one of the most difficult didactical concepts. The paper presents and analyses pupils’ conceptions of zero, especially their perception of zero as an even number.
It describes a teaching episode from 4th grade of primary school, taught by the author who recorded this episode and pupils’ comments and statements from her lesson (based on scheme-oriented education in which pupils’ ideas and reasoning play a key role). The author not only describes the course of the lesson but looks for the roots of various misconceptions and ideas as well as convenient tools and questions for their re-education.