Information about the title: Clear structure: systematic, integrative, and differentiated acquisition of basic knowledge in the main learning area with "Test yourself!" pages that connect with the second learning area and offer parallel differentiation upon request as well as support pages. Preparation for class tests or project proposals on "Fit in" pages. Fundamental principles: diagnostics, differentiation, teaching competencies. Free online diagnostics. Consistent differentiation at different levels. Learning transparency: advance organizers, self-diagnosis. Process-oriented preparation for class tests. Independent and cooperative learning. Information about the series output: clear structure: systematic, integrative, and differentiated acquisition of basic knowledge in the main learning area with "Test yourself!" pages that connect with the second learning area and offer parallel differentiation upon request as well as support pages. Class color.