Data in computers is stored and transmitted as a series of zeros and ones. Learners explore how to represent numbers using just these two symbols, through a binary system of cards. When the card's dots are showing, its value is 1 and the dots are counted. When the card's dots are not showing, its value is 0 and the dots are not counted. Learners model binary counting to discover patterns and represent numbers. This activity includes three worksheet activities (1 introductory and 2 extensions) for learners to complete and background information for the instructor.