This essential teaches basic formulas, methods and ideas of classical financial mathematics. Since classical financial mathematics makes do with elementary mathematical tools, any interested reader with average mathematical school knowledge can easily follow this text. The core of the text is the calculation of interest and compound interest, annuity calculation, amortization calculation and price calculation. A large number of practical examples illustrate the mathematical questions. This Springer essential is a translation of the original German, done with the help of artificial intelligence (machine translation by the service DeepL.com). A subsequent human revision was done primarily in terms of content, so that the book will read stylistically differently from a conventional translation. Springer Nature works continuously to further the development of tools for the production of books and on the related technologies to support the authors.