Educators expect that students be able to make informed decisions about science-related problems in their everyday lives. Engaging science in such problems often entails evaluating available evidence for given arguments. This study explores how students use inscriptions as evidence to argue about socioscientific issues. Fifth- and sixth-grade students (N = 102) in two intact classrooms completed written argument tasks in which they were asked to cite given inscriptions to support their decisions about energy use or genetically modified organisms. Qualitative content analyses of these written arguments, which focused on the coordination between inscriptions and claims, show three patterns of rhetorical use of inscriptions: "seeing is believing," "believing is seeing," and "asserting is inferring." What counts as evidence was not the inscriptions per se, but the rhetorical functions they performed in particular arguments. These findings suggest that justifying socioscientific decisions is functionally different from explaining scientific phenomena. Linking these two activities in school may help students more productively engage with science in their everyday lives.