Although according to the Finnish curriculum the learning environment in mathematics lessons should promote supportive interaction, Finnish pupils' attitudes toward and self-beliefs regarding mathematics deteriorate during basic education. This article investigates emotion work in teacher-student interaction in Finnish mathematics classrooms; the aim is to identify and suggest situational sources for the negative affective stances that seem to prevail among Finnish pupils. For the specific topic of analysis, we chose IRE sequences, especially teachers' responses to pupils' incorrect answers. Our data consist of ten sixth-grade mathematics lessons. Using conversation analysis as our method, we analyze examples that highlight the participants' emotion work displayed in verbal and non-verbal practices. We suggest that it is pedagogically important that the teacher practices communicating the message that incorrect answers are appropriate student contributions and that in analyzing interaction in mathematics education it is important to pay attention to the emotional aspects of the interaction.