“…From these descriptions we have drawn the following conclusion: If mathematics is understood and practiced as a living and developing organism including guiding problems, heuristic strategies for solving problems, different types of representation (enactive, iconic, symbolic), different ways of communication, exercises at different levels, the search for structures and patterns, proofs, and applications to internal or real-world problems, then the organization of knowledge in order to make it understandable to students is part and parcel of this "well-understood mathematics" at any level, beginning with early math (Kinnear and Wittmann 2018).…”