The textbook is intended for studying the fundamental ideas and methods of financial mathematics with particular attention to the theory of interest rates and its practical applications. Its structure is designed to familiarize students with the theory of interest rates, cash flow management, annuity calculation methods, and investment project analysis. In addition, it covers techniques for valuing bonds and stocks, calculating net present value and internal rate of return, as well as the fundamentals of portfolio theory with consideration of mean deviation. The textbook combines theoretical foundations with practical examples that help students develop their analytical skills.