A collection of materials centered around students constructing productive and impactful meanings in linear algebra.  The materials heavily leverage metaphors and visualizations as students build a deep conceptual understanding of linear algebra.

See:

Meyer, J. S. (2024). Teaching Matrix Multiplication with Impactful and Productive Meaning. PRIMUS, 1–21.
https://doi.org/10.1080/10511970.2024.2310246

A collection of investigations in which students start with basic axioms of sets and fields and, over one semester, construct foundational results for vector spaces, subspaces, linear maps, bases, eigentheory, and inner products.  The sequencing of investigations is carefully laid out and proofs are carefully scaffolded.  Each investigation involves tasks requiring students to explore, justify, reflect, and explain.

A collection of investigations in which students start with basic axioms of the plane and, over the span of two semesters, construct foundational results in Euclidean, inversive, and hyperbolic geometry of the plane.  The sequencing of investigations is carefully laid out and proofs are carefully scaffolded.  Each investigation involves tasks requiring students to explore, justify, reflect, explain, and visualize.