A successful career in physics is impossible without a deep knowledge of its language – mathematics. The goal of this course is to teach the basic mathematical methods used in modern sections of physics: condensed matter physics, disordered systems theory, low-dimensional nanostructure physics, etc. The course is aimed at developing mathematical thinking and the ability to apply well-developed mathematical techniques to solve common types of physics problems. Classes are held in the form of seminars, which provide the theoretical foundations of the mathematical methods used, and then analyze examples of problem solving. A wide range of issues is considered, from the theory of functions of a complex variable and special functions to selected issues of percolation theory and the basics of group theory.