Mathematics at School magazine is the most authoritative periodical for mathematics teachers, with a history of more than 70 years. More than one generation of teachers considered and considers him a faithful adviser and reliable assistant in their work. Every year, before starting classes, the teacher reflects on: How to build the course of the lesson? How to plan the presentation of a particular topic? How to make the most competent planning of educational material in different profiles of the school course of mathematics? How to optimally select tasks to test the knowledge of schoolchildren?