A primary teacher's developing understanding of mathematical reasoning

To support teachers in their quest to incorporate reasoning as a mathematical proficiency as espoused in the Australian Curriculum: Mathematics, a professional learning research project using demonstration lessons was carried out. This paper reports on the impact of demonstration lessons on one participating teacher’s pedagogical knowledge about reasoning. The growth in this teacher’s knowledge was analysed using a phenomenographic framework established to evaluate teachers’ development in mathematical reasoning. The results show that demonstration and subsequent trial lessons contributed to her growth.