We describe a formative assessment approach called whole-class think alouds, which foster evidence-based instructional practices and promote the goal of assessment to promote learning. They allow students to collaborate and orally communicate their problem solving.

### Joanne Caniglia and Michelle Meadows

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.

### Joshua Jones

Explore a lesson in which students used conditional probability to conjecture a predictive text algorithm, which, if translated into a coding language, could teach a computer to predict what a user wants to type, given the previous words in a message.

### Nancy Anderson

The questions that teachers ask to elicit student reasoning—often referred to as *press for reasoning*—help students explicate the concepts and principles that undergird their strategies. This article describes the term, addresses its benefits and challenges, and offers three routines.

### Melissa A. Gallagher, Laura Ellis, and Travis Weiland

Teachers can employ four strategies that students in K–12 already know and use in literacy to better comprehend mathematical word problems.

### Steve Ingrassia and Molly Rawding

Problems to Ponder provides 28 varying, classroom-ready mathematics problems that collectively span PK–12, arranged in the order of the grade level. Answers to the problems are available online. Individuals are encouraged to submit a problem or a collection of problems directly to mtlt@nctm.org. If published, the authors of problems will be acknowledged.

### Brian Mahaffey

This department provides a space for current and past PK–12 teachers of mathematics to connect with other teachers of mathematics through their stories that lend personal and professional support.

### Michael Daiga and Shannon Driskell

The two provided activities are geared for students in middle school to facilitate and deepen their understanding of the arithmetic mean. Through these activities, students analyze visual representations and use a special type of statistical thinking called transnumerative thinking.