ABSTRACT
There is evidence for recommendations to link mathematics teacher education (MTE) closely to school mathematics and to emphasize proving why rather than proving that when teaching reasoning and proving (R&P) in schools. In spite of that, we suggest not to take the implication that MTE focuses on proving why to extremes. We outline the background, framework and results of a pilot to an intervention study that seeks to address the problems of R&P in MTE. The results suggest that teachers face more problems with R&P than expected and have difficulties selecting classroom situations in need of a mathematical justification, let alone developing justifications and supporting their students’ learning of R&P. This supports our suggestion that a dual emphasis on proving that and proving why is needed in MTE.
