Productive struggle is an essential part of mathematics instruction that promotes learning with deep understanding. A video scenario is used to provide a glimpse of productive struggle in action and to showcase its characteristics for both students and teachers. Suggestions for supporting productive struggle are provided.

### Katherine Baker, Naomi A. Jessup, Victoria R. Jacobs, Susan B. Empson and Joan Case

### LouAnn H. Lovin

Moving beyond memorization of probability rules, the area model can be useful in making some significant ideas in probability more apparent to students. In particular, area models can help students understand when and why they multiply probabilities and when and why they add probabilities.

### Erell Germia and Nicole Panorkou

We present a Scratch task we designed and implemented for teaching and learning coordinates in a dynamic and engaging way. We use the 5Es framework to describe the students' interactions with the task and offer suggestions of how other teachers may adopt it to successfully implement Scratch tasks.

### Alyson E. Lischka and D. Christopher Stephens

The area model for multiplication can be used as a tool to help learners make connections between mathematical concepts that are included in mathematics curriculum across grade levels. We present ways the area model might be used in teaching about various concepts and explain how those ideas are connected.

### Debasmita Basu, Nicole Panorkou, Michelle Zhu, Pankaj Lal and Bharath K. Samanthula

We provide an example from our integrated math and science curriculum where students explore the mathematical relationships underlying various science phenomena. We present the tasks we designed for exploring the covariation relationships that underlie the concept of gravity and discuss the generalizations students made as they interacted with those tasks.

### Alyson E. Lischka, Kyle M. Prince and Samuel D. Reed

Encouraging students to persevere in problem solving can be accomplished using extended tasks where students solve a problem over an extended time. This article presents a structure for use of extended tasks and examples of student thinking that can emerge through such tasks. Considerations for implementation are provided.

### Gabriel Matney, Julia Porcella and Shannon Gladieux

This article shares the importance of giving K-12 students opportunities to develop spatial sense. We explain how we designed Quick Blocks as an activity to engage our students in both spatial reasoning and number sense. Several examples of students thinking are shared as well as a classroom dialogue.

### Michael J. Bossé, Kathleen Lynch-Davis, Kwaku Adu-Gyamfi and Kayla Chandler

Teachers can use rich mathematical tasks to measure students' conceptual understanding.

### Kristen E. Reed and E. Paul Goldenberg

Use these principles for constructing and choosing tasks that blend seamlessly into the school day, guide your teaching, and preserve precious instructional time.

### Lorraine M. Baron

Assessment tools–a rubric, exit slips–inform instruction, clarify expectations, and support learning.