How are we to account for the power of numbers in the modern world? Starting from the question of what it means to know something with numbers, this course examines a range of theoretical and methodological approaches to the study of quantification in the history of science and science and technology studies (STS). Secondary literature and historical texts will survey the rise of quantification across scientific disciplines as well as in attempts to know and control markets, environments, bodies, and populations. As a group, we will consider what kinds of knowledge and forms of governance are produced through quantification, how something (or someone) becomes quantifiable, and how quantitative objects or practices can be analyzed as historical or ethnographic sources. Students will have the opportunity to compare the study of data in different fields and to explore how an analysis of quantification might be relevant to their own research.