Information about the title: A well-structured task apparatus trains the application of new contents. Colors and symbols clearly indicate three different levels and tasks for training process-related skills. Different approaches make it easier for various types of learners to get started, whether discovering through everyday and inner-mathematical questions or reading example-related teaching texts. Numbers and sizes enable all learners to understand and actively learn. Topic pages encourage networking and interdisciplinary, project-related work. Method pages train mathematical argumentation and the use of mathematical tools. Mixed exercises provide a deeper insight into mathematical relationships and everyday applications. A self-diagnosis test provides feedback on individual progress.