Mathematics teaching is highly complex and this complexity is clearly visible in classroom interactions. These interactions involve multiple goals, including those specific to mathematics learning, but they also involve moment-to-moment decision-making by teachers that are influenced by social and mathematical norms of interaction within the classroom, as well as teachers’ knowledge, beliefs and values. As a field we are seeing a shift towards more large-scale studies of mathematics classroom interaction. These studies focus on which interactional practices are supportive of mathematics learning but there is a challenge in considering interactional strategies that are highly valued but are also highly contingent upon the interactional context in which they occur, such as responsiveness to students’ thinking. This challenge is illustrated through an extract from an interaction around reflecting shapes where different interactional strategies are in tension.