The aim of this study is to investigate into the use of discussions in the classroom to help the pupils develop a deeper understanding of mathematical concepts and operations. The empirical data contain interviews with two teachers and observations from their lessons. The purpose of the interviews was to find out what importance the teachers ascribed to the ability of their pupils to talk about mathematics, and how they organised their classes to encourage mathematical discussions. With the observations, I was able to see the interaction in the classroom and hear discussions between the teacher and the pupils, as well as between the pupils themselves.

The interviewed teachers proved to share my own belief in the results of researchers like Malmer (1999) and Löwing (2006) about the importance of verbal discussion, argumentation and reflection during mathematics classes. But convictions derived from the research of others are one thing, the practical application of the wisdom in the classroom another. My study showed that it is a very complex problem for the teacher to create a classroom that allows and enables mathematical discussions between the pupils themselves. The teachers have to plan their classes well and form smaller groups with the mathematical conversation in mind, if the pupils are to use, discuss and reflect upon mathematical concepts and talk about different strategies for solving a problem. There is also a need for individualisation. The teachers have to use many different methods and allow a variety of materials for the pupils to work with, if they are all to be involved in the mathematical conversation in the classroom.