In this paper, we discuss pre-service mathematics teachers' professional gains from a university-school collaboration where they were given opportunity to observe two teacher educators' instructional practices in a 6th grade classroom, interact with students in one-to-one fashion and reflect on the teacher educators' and their own practices. Three pre-service teachers out of nine volunteers attended all modelling and practice sessions for 20 weeks. The data collected through interviews, field notes, videos of both class activities and group reflections and written reflections. All nine pre-service teachers appreciated the value of working closely with students in a school setting rather than just observing the teachers. Furthermore, they gained experience about noticing students' mathematical thinking and critically analyzing their own practices.