Specific teacher moves and lesson planning can facilitate student empowerment in the middle school classroom.

### Stephen Phelps

### Edited by Anna F. DeJarnette

A monthly set of problems targets a variety of ability levels.

### P. Reneé Hill-Cunningham

Hundreds of species of animals around the world are losing their habitats and food supplies, are facing extinction, or have been hunted or otherwise negatively influenced by humans. Students learn about some of these animals and explore multiple solution strategies as they solve this month's problems. Math by the Month features collections of short activities focused on a monthly theme. These articles aim for an inquiry or problem-solving orientation that includes four activities each for grade bands K–2, 3–4, and 5–6.

### Sarah Ferguson

Explore the creation of a unique problem-based learning (PBL) experience.

### Susan F. Zielinski and Michael Glazner

Help students stop making typical, persistent errors related to misconceptions about exponents, distribution, fraction simplification, and more.

### Stephen Phelps

### Edited by Anna F. DeJarnette

A monthly set of problems is aimed at a variety of ability levels.

### Brandy Crowley and Tracy Harper

**What is the most exciting day** of the school year? Field trip day! Organizing a smooth field trip requires mathematical thinking. After solving these problems, have students create math questions about their own field-trip experiences.

### Kristen Lew and Juan Pablo Mejía-Ramos

This study examined the genre of undergraduate mathematical proof writing by asking mathematicians and undergraduate students to read 7 partial proofs and identify and discuss uses of mathematical language that were out of the ordinary with respect to what they considered conventional mathematical proof writing. Three main themes emerged: First, mathematicians believed that mathematical language should obey the conventions of academic language, whereas students were either unaware of these conventions or unaware that these conventions applied to proof writing. Second, students did not fully understand the nuances involved in how mathematicians introduce objects in proofs. Third, mathematicians focused on the context of the proof to decide how formal a proof should be, whereas students did not seem to be aware of the importance of this factor.