Which One Doesn’t Belong? a picture book for children written and illustrated by Christopher Danielson, features a thoughtfully designed set of four shapes on each of the book’s vibrant pages. When asked, “Which one doesn’t belong?” each of the shapes has the potential to provide the correct response. Students are naturally led to shift their focus to justifications and arguments based on the geometric properties of the shapes because all of their answers are correct answers.
Danielson shows how to facilitate rich discussions and teach mathematical argumentation using Which One Doesn’t Belong? in the companion teacher’s guide, which can be purchased under the ISBN number 978-1-62531-081-1. He demonstrates how to listen to students’ ideas about shapes with respect and attentiveness. Danielson summarizes the research that has been conducted on how children learn geometry, discusses the place of geometry in the overall mathematics curriculum, and provides a wealth of helpful advice regarding the many different ways in which Which One Doesn’t Belong? can be used in the classroom. He also discusses the mathematical ideas that are likely to emerge on each page, and he helps teachers anticipate and think about students’ likely answers by drawing from his direct experience using Which One Doesn’t Belong? At several different grade levels. This information is drawn from his direct experience.
The majority of educational programs reduce the study of geometry to little more than vocabulary exercises. Which One Doesn’t Fit in the Picture? as well as the guide that goes along with it is potent and adaptable resources that teachers can use to spark animated conversations and in-depth learning about shapes with students of all ages.”