We know that problem solving is an effective way for students to learn to think mathematically and to acquire deep knowledge and understanding of the mathematics they are learning. Simply problematizing the mathematics curriculum, however, does not help constitute the practice that teachers want or students need. Equally, infusion of problem-based learning into the mathematics curriculum does not help with the transformations we want to see in our classrooms. What we need are a set of tools that, along with good problems, can build thinking classrooms. In this presentation, Dr. Peter Liljedahl looks at a series of such tools, emerging from research, that can help to build an environment conducive to problem-based learning. He will unpack his research that has demonstrated that a problem-based learning environment and culture can quickly be established, even in classrooms where students resist change.