Carlos LópezLeiva is an Associate Professor in Bilingual and Mathematics Education in the Department of Language, Literacy, and Sociocultural Studies at the University of New Mexico, whose work focuses on being part of and working in teaching and learning (in- and out-side of school) ecologies—through relational approaches in social interactions, language use, task design, and problematizing what counts as mathematics—that mediate members’ participation in and meaning making of mathematical practices across communities.