On the first block of the course of mental arithmetic for teachers, you will learn the definition of "mental arithmetic", the purpose of the course, learn to count two-three-four-digit examples on soroban, using all the formulas, get acquainted with the concept of mental counting. The course is suitable for those who want to develop their abilities for themselves, and for those who want to teach this course. But beginning teachers need to pass all three blocks. In order to learn multiplication and division in soroban, go through the second block of the course. For those who want to get knowledge on the method of teaching the course of mental arithmetic, you should pass the third block of the course.