Effective teachers must simultaneously attend to many facets of the classroom, including the mathematics topic to be learned, the way students think about that topic, and the cultural contexts in which the topic may be situated. In this study, we focus on that to which prospective teachers attend in a teaching scenario involving a culturally-based nonstandard algorithm. In this scenario, a teacher dismisses a multi-digit subtraction algorithm because it is different from the standard algorithm. We surveyed 23 prospective elementary teachers, and using open coding we found that while most of the prospective teachers disagreed with the teacher's dismissal of the algorithm, their disagreement focused on mathematical or student thinking arguments, but not on culturally based arguments. We discuss the implications of these findings.