The textbook "Faktor 7 SJ. Mathematics for Secondary School" is aimed at students in secondary school and is specifically aligned with the core curriculum of Lower Saxony. Written by Bernd Wurl, Max Schröder, and Alexander Wynands, it offers a comprehensive and structured approach to mathematical topics that are important for educational training. The hardcover ensures high durability, while the 192 pages in German contain a variety of exercises and explanations that enhance the understanding of mathematics. Weighing 515 grams and measuring 19 cm in width and 26 cm in height, the book is compact and easy to transport. The first edition of the work was published in 2006, making it a proven teaching resource for mathematics instruction. The book is produced in Germany and provides a solid foundation for mathematical learning in secondary school.