In this volume, which completes his history of numbers, Georges Ifrah first of all recapitulates for the reader the steps in mathematical notation which he has made familiar. He considers algebra and its relationship with reason; how it has opened the way to new advances in computation. He introduces the reader to the departure made from the decimal Base 10 to the spread of the binary Base 2, the foundation for computing. He then takes us through the origins and progress of the computer revolution, going back to calculating machines invented more than 100 years ago. He finishes with a synthesis of the development of numbers technology as a function of logic, and concludes with a view to our future with technology.