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

### Amanda Milewski and Daniel Frohardt

Few high school students associate mathematics with playfulness. In this paper, we offer a series of lessons focused on the underlying algebraic structures of the Rubik's Cube. The Rubik's Cube offers students an interesting space to enjoy the playful side of mathematics, while appreciating mathematics otherwise lost in routine experiences.

### Christopher Harrow and Ms. 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.

### Sandra M. Linder and Amanda Bennett

This article presents examples of how early childhood educators (prek-2nd grade) might use their daily read alouds as a vehicle for increasing mathematical talk and mathematical connections for their students.

### Julie M. Amador, David Glassmeyer, and Aaron Brakoniecki

This article provides a framework for integrating professional noticing into teachers' practice as a means to support instructional decisions. An illustrative example is included based on actual use with secondary students.

### Zachary A. Stepp

“It's a YouTube World” (Schaffhauser, 2017), and educators are using digital tools to enhance student learning now more than ever before. The research question scholars need to explore is “what makes an effective instructional video?”.

### Tim Erickson

We modify a traditional bouncing ball activity for introducing exponential functions by modeling the time between bounces instead of the bounce heights. As a consequence, we can also model the total time of bouncing using an infinite geometric series.

### 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.

### Travis Lemon

NCTM has provided rich resources through the publication of practitioner journals for decades and is now leading the way once again with a digital first dynamic publication focused on the learning and teaching of mathematics. This is a rich opportunity for teachers to engage, to learn and to go.