Purchase the book

Danielson’s book reveals the wonder and freedom of expression that many children don’t often experience in mathematics. A single, simple question puts children in a position to speak mathematically even at early ages. Ask students of all ages ‘Which one doesn’t belong?’ and revel in the reasoning and conversation that results.

— Dan Meyer

How can I recommend this highly enough? Christopher Danielson emphasizes the stimulation of curiosity and that math is about making precise things that we—and children—can informally observe, without having to learn any mathematical language first. Which One Doesn’t Belong? is a glorious book for adults and children to explore together, and the Teacher’s Guide makes it into a profound mathematical resource.

— Eugenia Cheng, pure mathematician, University of Sheffield and School of the Art Institute of Chicago, and author of How to Bake Pi


Visit the Stenhouse website to purchase Which One Doesn’t Belong. The Teacher’s Bundle includes the student book, the teacher’s guide, and digital access to both.

You can also purchase additional copies of the student book in single, hardcover copies, or paperback bundles of 5.