An escape room can be a great way for students to apply and practice mathematics they have learned. This article describes the development and implementation of a mathematical escape room with important principles to incorporate in escape rooms to help students persevere in problem solving.

### Micah S. Stohlmann

Dude Perfect has one of the most popular YouTube channels in the United States. An example mathematical activity connected to a Dude Perfect video is described along with the incorporation of assessing and advancing questions.

### Anne Quinn

The paper discusses technology that can help students master four triangle centers -- circumcenter, incenter, orthocenter, and centroid. The technologies are a collection of web-based apps and dynamic geometry software. Through use of these technologies, multiple examples can be considered, which can lead students to generalizations about triangle centers.

### S. Asli Özgün-Koca and Matt Enlow

In this month's Growing Problem Solvers, we focused on supporting students' understanding of congruence and similarity through rigid motions and transformations. Initial understandings of congruence and similarity begin in first grade as students work with shapes in different perspectives and orientations and reflect on similarities and differences.

### Steve Ingrassia and Molly Rawding

Problems to Ponder provides 28 varied, classroom-ready mathematics problems that span grades PK-12, arranged in order of grade band. Links to the problem answers are available in this department.

### Mathew D. Felton-Koestler

Share news about happenings in the field of elementary school mathematics education, views on matters pertaining to teaching and learning mathematics in the early childhood or elementary school years, and reactions to previously published opinion pieces or articles. Find detailed department submission guidelines at http://www.nctm.org/WriteForTCM.

### Priya V. Prasad

Assess the robustness of students’ understanding of polygons and move students beyond drawing to constructing geometric shapes.

### Hyunyi Jung

To witness a spike in students' mathematical abilities, explore a model-eliciting activity.

### Sherry L. Bair and JoAnn Cady

Solutions to a November 2013 Solve It problem are discussed, and the procedures used with problem solving are explored.

### Nicole L. Fonger

Designing activities to reconcile multiple representations supports students' focus and fluency.