The goals for STEM education are largely agreed, nationally and internationally. Work over the last 30 years in the research and development community, epitomized by ISDDE, has shown how to develop tools and processes for teaching, assessment and professional development that enable typical teachers to teach much better mathematics and science much more effectively. Why is this not reflected in most classrooms, and what can be done about it? This paper presents an analysis of the barriers to progress and an explicit model for tackling them.

Serendipity has been defined as the occurrence and development of events by chance in a happy and beneficial way. Beauty is described by one dictionary as "a combination of qualities, such as shape, color, or form, that brings pleasure to the senses or pleasurably exalts the mind or spirit." This paper gives examples of how these two aspects of experience have influenced what I would like to see in mathematics classrooms and my curriculum development work to engender them, prior to and through the work of the University of Chicago School Mathematics Project.

Since 2007, a new interdisciplinary course 'Nature, Life and Technology' (NLT) has been taught in more than 200 Dutch senior high schools by teams of teachers, in addition to the regular courses in mathematics, physics, chemistry, biology and earth science. The goals of NLT are to motivate students for a career in science and technology and to show them the coherence between the traditional STEM subjects. Teams of teachers and experts from research and industry developed more than 80 interdisciplinary modules. This paper describes the development and implementation process, focusing on the design principles in the development of standards, development of materials, professional development (PD), implementation at schools and monitoring activities. From this experience, several lessons can be learned for comparable challenges.

Fostering productive groupwork is a goal for many educators, but it can be difficult to implement effectively in mathematics classrooms. We have developed an approach, and a corresponding set of new tools, intended to support student participation in mathematically rich collaborative learning activities. This paper provides an overview of this 'Distributed by Design' approach. We elaborate key principles by illustrating three variations, in which we alternately distribute distinct but interdependent mathematical objects, views, or tools to each student in a cooperative group, and ask participants to coordinate those elements in completing a shared task. This approach is implemented with our MathNet software.