Mathematics. Grades 9-11. Practical exam preparation. Part 1. Numbers, numerical equalities.

The proposed textbook, aimed at a wide range of readers and released in four parts, covers most of the topics studied in high school mathematics courses. The examples and problems presented in this book have been tested and used by the authors at the preparatory department of Lomonosov Moscow State University for several years to enhance the mathematical level of high school students.
The textbook is primarily of an applied nature. The theoretical foundations are presented fairly comprehensively and logically, but in a concise manner, without detailed derivations and proofs that could complicate the use of the book. The problems are arranged in increasing order of difficulty and are accompanied by answers, and in some cases, solution hints.
The authors hope that this textbook will be interesting and informative for many readers, from high school students to mathematics teachers, as well as for students in preparatory departments of universities.