Build on teachers' and students' understanding of division by emphasizing partitive and measurement models and strategies for writing quality division story problems.

### Vanessa M. Battreal, Vanessa Brewster and Juli K. Dixon

Using donuts to contextualize and enrich mathematical discourse can sweeten students' understanding of how to interpret the remainder in a division problem.

### Marie Wright

This department showcases students' in-depth thinking and work on previously published problems. The September 2012 problem scenario helps students build number sense and measurement sense. This problem would make a nice addition to observances Fire Prevention Week (October 6–12).

### Amanda Sibley and Terri L. Kurz

Here is a simple way to turn an ordinary whiteboard into an interactive tool that allows students to design and build pathways along which a sliding object will flow—within certain constraints—to reach its final destination. Students must reason, conjecture, test, conjecture again, and then retest their design features to determine a solution to the presented investigation.

### Kimberly A. Markworth

Working with repeating patterns is important for K–grade 2 students because of the connections they will make in later grades with related mathematical ideas.

This department showcases students' in-depth thinking and work on previously published problems. Embedded in the Field Day problem is the big idea of place value. Students explore the scenario of organizing pinnies (scrimmage vests) into bundles of ten, making it easier to distribute them to eight teams participating in a field day.

These problems are situated in the context of firefighting to promote problem solving and critical thinking.

### Angela Marie Frabasilio

Let students find the connecting thread to create, illustrate, and share word problems to bridge school math and real-life math.

### Julia M. Aguirre, Cynthia O. Anhalt, Ricardo Cortez, Erin E. Turner and Ksenija Simic-Muller

Two major challenges in mathematics teacher education are developing teacher understanding of (a) culturally responsive, social justice–oriented mathematics pedagogies and (b) mathematical modeling as a content and practice standard of mathematics. Although these challenges may seem disparate, the innovation described in this article is designed to address both challenges in synergistic ways. The innovation focuses on a mathematical modeling task related to the ongoing water crisis in Flint, Michigan. Through qualitative analysis of instructor field notes, teachergenerated mathematical models, and teacher survey responses, we found that teachers who participated in the Flint Water Task (FWT) engaged in mathematical modeling and critical discussions about social and environmental justice. The evidence suggests that integrating these 2 foci–by using mathematical modeling to investigate and analyze important social justice issues–can be a high-leverage practice for mathematics teacher educators committed to equity-based mathematics education. Implications for integrating social justice and mathematical modeling in preservice and in-service mathematics teacher education are discussed.

### Sharon A. Edwards, Robert W. Maloy and Gordon Anderson

Learning mathematical problem solving is as easy as 1, 2, 3 when teachers use flexible instructional strategies.