Primary-grade math concepts come into play when a club must decide the best way to sell their charity popcorn. The Community Champions are a varied cast of kids--an unobtrusive mix of genders, races, and one who uses a wheel-chair--who do good works around town. Occasionally Driscoll drifts into the too angelic: "The Champs were quiet as they read the messages" of thanks from previous year's Thanksgiving project. Other times she speaks what's better left unsaid: "The more popcorn we sell, the more families we help!" Lizzie burbles. But for the most part, the kids are trying to maximize sales through the deployment of business math--this book is part of the Math Matters series, each of which targets a specific math concept--including distribution and averaging, with terms such as median, mean, value, mode, and range set aside as boxed items for further explanations. The kids even learn how to compete with the grocery store to find the best price margin. In the end, the artwork (mostly depictions of swarms of kids having a good time) and the text feel right: their teacher is proud of their spirit, and the kids get a warm feeling from doing something selfless and meaningful. Three other Math Matters titles publish simultaneously: A Fishy Mystery, by Lisa Harkrader and illustrated by Cary Pillo, introduces Venn Diagrams; Let's Go, Snow!, by Eleanor May and also illustrated by Pillo, looks at temperature measurement; and Otto and the New Girl, by Nan Walker and illustrated by Amy Wummer, explores symmetry.