This chapter is about teachers’ assessment of individual student’s knowledge and abilities in connection with students’ oral presentation of a mathematical group work assignment as a means for individual group work assessment. Thus, presenting a study about dialogical practices in four mathematical classrooms. The specific object is to show if, and if so, how classroom talk can create conditions for valid individual group work assessments. Participants were four teachers and 96 students in Year 5 (ages 11–12) and Year 8 (ages 14–15) in four compulsory schools in Sweden. Data consists of four video-recorded classroom talks after students’ presentations. Data has been analysed using an adapted version of the Cambridge Dialogue Analysis Scheme (CDAS) to code teachers’ and students’ dialogic and non-dialogic moves during classroom talk. The analysis shows that different communication patterns are created in the classrooms. The results display variations in dialogical practice in the four different schools, implying that teachers, to varying extents and in various ways, utilise the opportunity to ask questions to create dialogue. Based on these differences, we identified four types of classrooms, in which different teachers create different conditions for dialogical practice as a means for individual group work assessments.