This chapter examines the explanatory functions and lapses of the maternal mortality ratio, the most commonly used maternal health indicator. Unlike people, metrics can be tracked, graphed, compared across time and space, converted to dollars, inserted into equations, and statistically manipulated. They are politically useful, yet their political weight rests upon their claim to represent (in aggregate) actual people. The chapter juxtaposes evidence from research on maternal death in southeastern Africa with an analysis of the assumptions built into statistical models of maternal mortality. It shows how equations, like other ways of describing maternal death, are partial—and consequential—explanatory narratives.