In this technological age, digital devices are conspicuous examples of extraordinary complexity. When a user clicks on computer icons or presses calculator buttons, these devices channel electricity through a complex system of decision-making circuits. Yet, in spite of this remarkable complexity, the hearts of these devices are components that make simple decisions. This article describes an activity in which students learn how complex outcomes can result from simple decisions. Participants encounter a broad range of learning experiences, including electric-circuit construction, household wiring, digital systems, truth tables, and the concept of base-n number systems. The activity culminates in a dramatic demonstration of complexity from simplicity: Each student becomes an element in a digital decoder, translating a binary number into its decimal counterpart, which then appears on an illuminated, seven-segment display. (Contains 9 figures and 3 online resources.)