The authors describe a fourth-grade lesson that promotes understanding of angle as a dynamic figure through use of a real-world tool used by physical therapists to measure joint motion.

# Browse

### Robert Powers, Michelle Chamberlin, and William Dutmer

Growing Problem Solvers provides four original, related, classroom-ready mathematical tasks, one for each grade band. Together, these tasks illustrate the trajectory of learners’ growth as problem solvers across their years of school mathematics.

### Nasim Chenari

This article describes how fortuitous mathematical moments should be noticed, encouraged, embraced, and capitalized upon.

### Ken Keech, Betty Routhouska, and Nicole L. Fonger

Two high school algebra teachers and their students focused on examining population trends affected by the creation of a highway though a thriving African American community.

### Carrie Plank and Sarah Roller Dyess

Use these three strategies to support student perseverance and discourse about context.

### Amanda L. Cullen

Any ability grouping in mathematics education is an inequitable structure that perpetuates privilege for a few and marginality for others. Ability grouping practices often occur with good intentions; we want to understand children’s learning needs and then tailor the content,

### Alisan Boes, Duane C. Boes, and Nichola Hillis

We explore the statistical likelihood of one, or more, siblings in a family of nine surviving to 100 years of age.

### Joshua David Jones

To be literate in a society where the information shared online is often exploited, learners should be exposed to multiple aspects of contemporary predictive modeling. Explore a lesson in which students learned an algorithm used in practice to automate the process of making recommendations.

### Deanna Pecaski McLennan

This article describes how fortuitous mathematical moments should be noticed, encouraged, embraced, and capitalized upon.

### Douglas H. Clements, Shannon S. Guss, and Julie Sarama

Learning trajectories help teachers challenge children at just the right level for their best learning.