P. Ia. Galperin's theory on the steps of forming mental actions has wide applications in the field of teaching, especially teaching in early elementary grades. Starting from physical actions on external objects, spreading that action to words and finally internal actions. In fact, this is the psychological basis for forming learning actions for students and choosing appropriate teaching methods, opening up the way to apply theoretical research into teaching practice. Based on the research results of activity theorists, P.Ia.Galperin researched and proposed a theory of mental action steps (internal actions) and meticulously described each operation of learner's actions. The article proposes to apply the theory of steps to form intellectual actions according to the stages of P.Ia.Galperin and a teaching model based on intellectual development strategies in first grade students