We all learned that the ratio of the circumference of a circle to its diameter is called pi and that the value of this algebraic symbol is roughly 3.14. What we werent told though is that behind this seemingly mundane fact is a world of mystery which has fascinated mathematicians from ancient times to the present. Simply put pi is weird. Mathematicians call it a transcendental number because its value cannot be calculated by any combination of addition subtraction multiplication division and square root extraction. In this delightful laypersons introduction to one of maths most interesting phenomena Drs. Posamentier and Lehmann review pis history from prebiblical times to the 21st century the many amusing and mindboggling ways of estimating pi over the centuries quirky examples of obsessing about pi including an attempt to legislate its exact value and useful applications of pi in everyday life including statistics.This enlightening and stimulating approach to mathematics will entertain lay readers while improving their mathematical literacy.