With this book, you can learn all the formulas of addition and subtraction, multiplication and division, learn the method of explaining this course to students, the organization of the teacher’s work (lesson plan, working with parents, exams, standards, reports of the teacher, etc.). Mental arithmetic develops: Speed of thinking, Memory, Attentiveness, Assiduity, Photographic memory, Creative analytical thinking, Logics, memory. Fine motor skills of hands.