Experience becomes the foundation of teaching. "Knowledge grows. The teacher is not there to convey the material. Rather, their task is to mediate between students and knowledge," states Martin Kramer’s decisive didactic credo. For him, this interaction between students and knowledge has a name: research. He refers to Celestin Freinet: "What is really important is not the knowledge, not even the discoveries: What matters is the research." Martin Kramer’s experiential educational concept of teaching as an adventure enables students to recognize and understand mathematical structures in a hands-on and group-dynamic way. Joy in play, cooperation, and personal development are the cornerstones of his constructivist didactics. His students impress with outstanding performances. Impress? The performances are a positive.