This ethnographic article complicates the common wisdom that the American Jewish elite cares “obsessively” about its constituents’ numbers. The article shows the ways in which population numbers matter to American Jewish leaders but also how they matter differently to various sectors of the community. Alongside those who are eager speakers of the language of quantification, there are those who feel unease with what, they feel, creates a reductive and irrelevant conversation about Jewish life in the United States. The article argues that by using the language of numbers and debating affectively over its value, American Jews debate who they are as a collective and struggle to define what counts for the future of the community as a highly diverse, shifting, and assimilating minority group. Building on the metaphor of “accounting of the soul”—one prevalent in religious and public discourses calling to Jews to look at their inner-soul workings—the article suggests that numbers serve as an effective and affective proxy for divergent communal calculations and reflections. American Jewry presents a compelling case study with which to think through the affective attitudes toward quantification, the cultural value of numbers, and the polyvalent work that they do for collectives. [quantification, numbers, statistics, demography, affect, American Jewry].