The textbook "Mathematics 9. Student Edition" by Westermann is aimed at students in secondary schools in Bavaria and is specifically tailored to the requirements of the Lehrplan PLUS. It offers a comprehensive and modern approach to mathematical topics that helps learners navigate a rapidly changing society. The book combines proven teaching methods with innovative approaches to create a lively and engaging learning environment. The content is clearly structured and includes numerous highlight boxes, examples, and exercises that address the diverse learning needs of students. Additionally, the book promotes discovery-based learning and project work through thematic pages and station circuits offered at the end of each chapter. The integration of strategy boxes and strategy tasks supports the development of process-related competencies and provides learners with effective problem-solving strategies.