Agreed, I just wonder how many math teachers know how to use Python, or even code for that matter. A set of existing Notebooks could teach them how to code in this fashion, and provide example lessons for their students…but yes…I agree that getting students/teachers to create their own visuals is best. What about a site that enables teachers and their students to only write their equations, and their math converts to a visual automatically (no coding)?

I also wonder how much of mathematics can be visualized? Does this restrict the lessons to functions? By virtue of their input-output mechanism we can create with functions using graphs, contour maps, parametric curves/surfaces, vector fields and transformations. Are other areas of mathematics amenable to creating with visuals?