A workbook for students who have transitioned from secondary school to vocational high school or who still have deficits at the beginning of upper secondary education. The first part, "Staying Fit," reviews and deepens the most important topics from middle school. This section consists of four chapters (terms, equations, linear functions, quadratic functions). Each chapter begins with a self-assessment page featuring test tasks and detailed sample solutions. Here, the key rules and formulas are reiterated and presented. The exercise section includes further tasks and thematic excursions. The second part, "Getting Fit," addresses the new requirements and competencies that students will encounter in high school: modeling, applying strategies, and linguistic competence take on greater significance.