Mathematics teachers’ development and the understanding of what constitutes learning are an on going topic and highlighting the complexity in the processes of learning in and from practice. This study builds on the idea that mathematics teachers’ professional development needs to be based on their classroom practice (Goodchild, 2008; Kazemi & Franke, 2004). Teacher participating in a working group, a learning community, and reflect on their own teaching and students learning. Working collaborative the mathematics teacher developed understanding of mathematical communication and mathematical reasoning in their teaching algebra.