A team of teachers has been engaging in professional development together through their participation in the Sydney Catholic Schools Mathematical Expertise and Excellence initiative. As part of this, teachers apply their learnings from workshops by teaching lessons to their students under the observing eyes of their colleagues. In this way, they are able to support one another, giving feedback and picking up strategies to help them improve their own practice. Ultimately, as the teachers learn together, the quality of the instruction and learning for our students also strengthens. Furthermore, the students love having extra teachers to work with during their mathematics lessons.