Discusses aspects of Christopher Columbus' decision to sail west in order to reach Asia. Includes discussions concerning the shape and size of the earth as determined up to Columbus' time and conclusions he made during the journey based on his calculations. (MDH)

Shows that the experiment of the ancient Greek mathematician and geographer, Eratosthenes, can be replicated and used to teach geographic concepts. Eratosthenes calculated the most accurate ancient measurement of earth based on fundamental mathematics concepts and earth-sun relations. Includes instructions, illustrations, graphs, and historical…

Presents a proof of Euler's Theorem on polyhedra by relating the theorem to the field of modern topology, specifically to the topology of relief maps. An analogous theorem involving the features of mountain summits, basins, and passes on a terrain is proved and related to the faces, vertices, and edges on a convex polyhedron. (MDH)