During World War II, people hoped ENIAC (Electronic Numerical Integrator and Computer), one of the earliest computers, could help with the war effort. With little guidance, no instructions, and barely any access to the machine itself, Betty Snyder, Jean Jennings, and Kay McNulty used mathematics, electrical engineering, logic, and common sense to command a computer as large as a room and create the modern world. This fascinating chapter in history is brought to life with vivid prose by Tami Lewis Brown and Debbie Loren Dunn and with striking illustrations by Chelsea Beck.