How has NCTM leadership shaped the evolution of teaching and learning mathematics? What are your expectations for NCTM leadership?

### Christopher Harrow and Nurfatimah Merchant

Transferring fundamental concepts across contexts is difficult, even when deep similarities exist. This article leverages Desmos-enhanced visualizations to unify conceptual understanding of the behavior of sinusoidal function graphs through envelope curve analogies across Cartesian and polar coordinate systems.

### Dan D. Meyer

Students use computers outside and inside of math classes and they enjoy them immeasurably more outside of math class. That's because, outside of class, they use their computers in ways that are creative and social. The same can and must be true about computers inside of math class.