Mathematics coaching is complex work, and coaches must be supported to become experts in mathematics, mathematics instruction, and mathematics coaching. Using video and interview data from 12 mathematics coaches and one district administrator in one public school district in the southeastern USA, this qualitative study explores how the performative aspect of one group of mathematics coaches' "doing the math" routine opened up conversations about mathematics, mathematics instruction, and mathematics coaching. Findings indicate that as the coaches engaged in "doing the math" together, opportunities to discuss mathematics and mathematics instruction were opened up, while conversations about mathematics coaching rarely surfaced. In interviews, participants discussed the benefits and drawbacks of participating in "doing the math." Implications for future research and practice are discussed.