### Kuo-Liang Chang and Ellen Lehet

Defining a quadratic function through the slopes of its secant/tangent lines leads to the fundamental theorem of calculus (FTC) and an alternative way of understanding integration.

### David B. Custer and Ksenija Simic-Muller

We reflect on recent presentations at the NCTM annual conference and articles in MTLT that address statistics, data modeling, and data science. We observe that such presentations and articles are increasingly common, and encourage readers to use them in their teaching and write about their own adventures with data.

### Melissa Graham, Johana Thomas Zapata, Amy Roth McDuffie, Nicole Blake, Introduction and Reflection by Angela T. Barlow, David Custer, and Clayton Edwards

Lesson study supports teachers in learning about curriculum and effective teaching practices. We discuss a district-wide lesson study process used to explore and adopt a new curriculum.

### Robert Powers and Michelle Chamberlin

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.

### Kym Fry and Lyn D. English

Grade 4 students engage in problem solving through inquiry in an agricultural science context.

### Ricardo Martinez and Ji Yeong I

Ear to the Ground features voices from serveral corners of the mathematics education world.

### Joanna Papakonstantinou

Students create clever mathematical Valentine’s Day cards.

### Zachary Sweet and Tiffany Thibodeau

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.

### Blake E. Peterson, Douglas L. Corey, Benjamin M. Lewis, Jared Bukarau, and Introduction by: Wendy Cleaves

From the Archives highlights articles from NCTM’s legacy journals, previously discussed by the *MTLT* Journal Club.