The book "Encyclopedia of elementary mathematics", written by outstanding mathematicians Alexandrov, Marukushevich and Hinchin, is a unique work that combines deep knowledge and an accessible presentation of the foundations of mathematics. This encyclopedia is not just a textbook, but a real treasure trove of knowledge in which every reader can find answers to their questions, regardless of the level of preparation. From the very beginning, the authors immerse the reader in the world of numbers and formulas, offering an exciting journey through the basics of elementary mathematics. The book deals with such key topics as arithmetic, algebra, geometry, trigonometry, and even the basics of mathematical analysis. Each chapter is written taking into account the needs of both schoolchildren and students, as well as anyone who wants to refresh their knowledge or is simply interested in mathematics. Who can like this book? First of all, it is an ideal choice for schoolchildren and students who seek to deepen their knowledge and prepare for exams . But not only young people will find useful information in it adults who want to understand mathematical concepts or help their children with homework will also appreciate the accessibility and clarity of the presentation. In addition, the book will be of interest to teachers who are looking for quality materials for their lessons. The topics raised in the Encyclopedia of Elementary Mathematics cover a wide range of issues, ranging from simple arithmetic operations to more complex concepts such as theorems and proofs. The authors focus on how mathematics permeates our daily lives, from in-store calculations to data analysis in science and technology. This makes the book not only a tutorial, but also a practical guide for anyone who wants to understand how mathematics works in the real world. The style of the authors is clear and logical . They are able to explain complex things in simple language, which makes the material available to a wide audience. Alexandrov, Marukushevich and Khinchin are not just authors, but recognized masters of their craft, each of whom has made a significant contribution to the development of mathematics. Their previous works also deserve attention: for example, Aleksandrov’s Mathematical Analysis or Marukusevich’s Algebra, which have already become classics in their field. This book not only expands the horizons of knowledge, but also inspires further study of mathematics. Readers who are interested in topics such as logic, numerical sequences, geometric shapes and their properties will definitely find something new and exciting in it. The Encyclopedia of Elementary Mathematics will become a reliable assistant in the study and understanding of the basics, as well as open doors to more complex and interesting areas of science. Do not miss the opportunity to immerse yourself in the world of mathematics with this wonderful book. It will become your faithful companion in the study and understanding of elementary mathematics, as well as help to develop logical thinking and analytical abilities. Read, explore and discover the amazing world of numbers and formulas together with the Encyclopedia of Elementary Mathematics!