## The Event:

Professor Lothar Redlin is the co-author of calculus and pre-calculus textbooks, some of which are currently used in OSU math courses.

## Synopsis:

An important mathematical problem-solving principle is Adding Something Extra. We show how this principle was used to solve historically important problems, from “the Seven Bridges of Königsberg” to some significant Diophantine equations. Although every problem we consider will be easy to understand for anyone with a high school algebra background, many of them have led to the foundation of major areas of modern mathematical research.