Academic success, and the economic well-being it usually affords, is closely tied to math achievement. Key national indicators reveal decades of underperformance of African American males in mathematics. Scholars argue that the schooling experiences of Black males are highly-racialized, are often bereft of significance, and result in academic and social marginalization. The author reports findings from an eight-month participatory action research (PAR) project involving seven high-school aged Black males in South Los Angeles; students undertook research to empirically verify and qualitatively explore narratives concerning incarceration and university enrollment. Utilizing a critical ethnographic methodology to privilege student voice, the author shares how ‘low-performing’ students in an urban setting utilize their mathematical knowledge to become critically literate about these narratives. Highlighting two student-constructed counternarratives he terms mathematical counterstories, the author shows how students used data analysis to contradict dominant understandings about young Black males. The author argues math counterstories are a unique synthesis of critical and mathematical literacies that are supported through PAR. Implications for the re-orientation of high school-aged Black males towards mathematics are discussed.