Algorithms are used to solve problems. They’re used in math, computer programming, and on Wall Street, but we also use algorithms to tie our shoes or to bake a loaf of bread. On this week’s Please Explain, Daniel Bienstock, Professor of Industrial Engineering and Operations Research, at Columbia University, and Harry Lewis, Gordon McKay Professor of Computer Science at Harvard, tell us what algorithms are and how they work to solve problems both simple and complex. Harry Lewis is the author of Blown to Bits and Excellence without a Soul: Does Liberal Education Have a Future.