The Algebra 1 course is part of the continuous mathematics curriculum of the educational system developed by L.G. Peterson. It ensures the continuity of students' mathematical preparation from preschool to their transition to high school or attainment of secondary vocational education. The main objective of this course is to develop students' ability to learn, their intellectual and moral-spiritual development, and to maintain and support children's health. It aims to equip each student with a deep and solid foundation of mathematical knowledge, skills, and abilities tailored to their trajectory of self-development. These are necessary for continuing education in any profile of the high school and institutions of secondary vocational education in terms of technology and didactics, content, and methodology. The pedagogical instrument for achieving the set goals in the course at all stages of education, taking into account the age-related psychological characteristics of children's development, is the educational system of the activity-based teaching method developed by L.G. Peterson. It implements the methodological version of the systemic-activity approach.