The book includes the most important mathematical concepts and methods for a successful study of business or economics. It is more comprehensive than currently published works that are solely focused on bachelor's programs, making it a reliable companion from bachelor's to master's level. The content is deliberately explained not only through numerous examples but also formally presented and proven. It covers the elementary and formal foundations of mathematics, methods of linear algebra, the analysis of functions of one or more variables, as well as simple difference and differential equations. Furthermore, this 12th edition of the book features an expanded presentation of financial mathematics and an overview of models and methods for linear, nonlinear, and integer optimization.