Leading Czech expert in mathematics didactics.
After graduating from the Faculty of Mathematics and Physics of Charles University in Prague he worked at the CTU in Prague, the University of Agriculture in Žilina, the MFF in Bratislava and, since 1991, he has been teaching at the Faculty of Education of the Charles University in Prague. He leads a research team with whom he founded a recognized school of mathematics didactics. Together with several co-workers he began to expand the research of his father, the teacher Vít Hejný. His unique method is based on the fact that the teacher does not tell the children new information, pupils have to discover the magic of mathematics themselves. He has lectured at 13 international universities and over 30 international conferences. He is the author and co-author of 16 mathematical publications and more than 270 publications from mathematics didactics. He is, among other things, the holder of the medal of Ministry of Education.