Written by one of the foremost experts in high-performance computing and the inventor of Gustafson's law, Every Bit Counts: Posit Computing explains the foundations of a new way for computers to calculate that saves time, storage, energy, and power by packing more information into every bit than do legacy approaches. Both the AI and HPC communities are increasingly using the posit approach that Gustafson introduced in 2017, which may be the future of technical computing.What may seem like a dry subject is made engaging by including the human and historical side of the struggle to represent numbers on machines. The book is richly illustrated in full color throughout, with every effort made to make the material as clear and accessible as possible, and even humorous.Starting with the simplest form of the idea, the chapters gradually add concepts according to stated mathematical and engineering design principles, building a robust tool kit for creating application-specific number systems. There is also a thorough explanation of the PositTM Standard (2022), with motivations and examples that expand on that terse 12-page document.