The article presents the experience of work on improving the professional level of mathematics teachers in the city of Yakutsk, the Republic of Sakha (Yakutia) when they master the collective way of teaching. The basis of the system of methodological work with teachers is the system-activity approach, which includes each teacher in the creative community at different levels. In a modern school, the need for a teacher who is able to modernize the content of his activities has increased through a critical, creative rethinking and application of scientific achievements and advanced pedagogical experience in mastering new methods and technologies of teaching, including CWT. At the same time, this imposes a great responsibility on educational institutions, requires from teachers a versatile pedagogical erudition, deep knowledge in the field of the scientific foundations of the educational process, organization and methodology of teaching, education, development of students, a high level of professional and pedagogical skills. For this reason, the organization of scientific and methodological work within the framework of the methodological association is designed to provide effective assistance in improving the professional level of the teacher. The teacher should be able to receive timely information about new approaches, new technologies for teaching students, as well as the ability to discuss and find solutions to issues arising in practice, determine the content and study the features of the learning system he builds in changing conditions, including when mastering CWL.