While race, class, and gender are often treated as well-defined and static identities within mathematics education research, we explore gender, race and class as performances through the case of a middle school Black girl, Cameryn. Scenes from video artifacts are deconstructed using a hermeneutic process to reveal how Cameryn positions herself as a seemingly disinterested, resistant mathematics student through a façade we call "blackgirl face." Blackgirl face not only reflects the particularities of Black girlhood for Cameryn but provides a new conceptual lens for understanding mathematics learning as a performance, requiring and enabling children to simultaneously negotiate race, class, and gender.