"Selected Questions in Mathematics, Grade 9: Elective Course" by N.Y. Vilinkin and his team is a unique educational resource that not only deepens students' mathematical knowledge but also fosters critical thinking skills. Designed specifically for ninth-grade students eager to expand their mathematical horizons, this book prepares them for more challenging problems they will encounter in high school and on exams. Inside, you'll find carefully curated problems and questions covering a wide range of topics—from algebra and geometry to elements of combinatorics and probability theory. The book goes beyond simply providing solutions; it encourages readers to think independently, analyze problems critically, and explore creative approaches to problem-solving. Each section combines theoretical explanations with practical exercises, making learning both engaging and effective. Who will benefit from this book? Primarily, ninth-grade students looking to strengthen their math skills and those preparing for exams and competitions. Math teachers will also find valuable materials for lesson planning and extra practice sessions. Thanks to its clear language and logical structure, the book appeals to both high schoolers and math enthusiasts seeking to sharpen their skills. The topics covered are diverse and highly relevant. They include applying mathematical methods to real-life situations, developing logical reasoning, and preparing for future assessments. Vilinkin and his team emphasize that mathematics is not just a collection of formulas and rules but a world full of mysteries and discoveries. They demonstrate how mathematical ideas connect with other sciences and even art, making the study of this discipline richer and more captivating. The author's style is clear and accessible, making even complex concepts easy to grasp. N.Y. Vilinkin is a renowned Russian mathematician and educator, author of many textbooks and guides that have become classics in school education. His works, such as "Mathematics for Grade 7" and "Mathematics for Grade 8," have earned the trust and recognition of both students and teachers. Vilinkin is dedicated to making mathematics engaging and approachable, and this book is a shining example of that commitment. If you're looking for a high-quality resource to prepare for exams or simply want to deepen your understanding of mathematics, "Selected Questions in Mathematics, Grade 9" is an excellent choice. It’s not just a book but a powerful tool to unlock new horizons in the world of numbers and formulas. With its help, you'll not only succeed in your studies but also develop analytical skills that will serve you well in any area of life. Don’t miss the opportunity to take a step toward new knowledge and discoveries in mathematics. This book is your reliable companion on an exciting journey through the fascinating universe of numbers!