The foundational knowledge for successful mathematics teaching. Mathematics teachers are more successful when they possess a broad and well-connected understanding of mathematics, pedagogy, and educational sciences. What exactly constitutes the foundational knowledge necessary to effectively design mathematics lessons and optimally support and challenge students? This book provides answers for the subject of mathematics, covering both primary and secondary education. Renowned scholars present pedagogical insights and theories in a compact and illustrative manner that are part of the current state of mathematics teaching. You will gain foundational knowledge in the following three areas: teaching and learning mathematics, mathematical education, and principles of mathematics didactics.