Motivated by questions in cosmology, Geometry with an Introduction to Cosmic Topology uses Möbius transformations to develop hyperbolic, elliptic, and Euclidean geometries - three possibilities for the global geometry of the universe. GCT is freely available (html,pdf), and a bound copy can be purchased for $11.
A humorous account of the number 8, tracing its rise from an obscure integer between 7 and 9 to its eventual position among the greatest of real numbers. (For instance, did you know that 8 is the number tipping champion of the world?) A mercifully condensed version of this story appeared in Math Horizons.
Student resource website includes presentation slides, in-class activities, R tutorials and R activities, created in RStudio.
Student resources (html and pdf options), generated with bookdown in RStudio, including lecture notes and R tutorials, indexed with cross-references.