The Teacher's Bundle includes the 84-page Teacher's Guide, 36-page hardcover student book, and access to digital formats. 

Which One Doesn’t Belong? has won the Mathical Book Prize, which will be presented to Christopher Danielson at the National Math Festival in Washington, DC on April 22, 2017. The Mathical Book Prize is an annual award for fiction and nonfiction books that inspire children of all ages to see math in the world around them.

Every colorful page of Christopher Danielson’s children’s picture book, Which One Doesn’t Belong?, contains a thoughtfully designed set of four shapes. Each of the shapes can be a correct answer to the question “Which one doesn’t belong?” Because all their answers are right answers, students naturally shift their focus to justifications and arguments based on the shapes’ geometric properties.
 
In the companion teacher’s guide, Danielson shows how to facilitate rich discussions and teach mathematical argumentation using Which One Doesn’t Belong? He models how to listen closely and respectfully to students’ ideas about shapes. Danielson synthesizes research about how children learn geometry, discusses the role of geometry in the mathematics curriculum, and gives plenty of practical advice about different ways to implement Which One Doesn’t Belong? in classrooms. He also discusses the mathematical ideas likely to emerge on each page and—drawing from his direct experience using Which One Doesn’t Belong? at several different grade levels—helps teachers anticipate and think about students’ likely answers.
 
Most curricula treat geometry as little more than vocabulary lessons. Which One Doesn’t Belong? and its accompanying guide are powerful, flexible resources teachers can use to provoke lively discussions and deep learning about shapes with students of all ages.

How Many? is not like other counting books.

In How Many?, there are multiple things to count on each page. Students might count one pair of shoes, or two shoes, or four corners of a shoebox. They might discuss whether two shoes have two shoelaces, or four. They might notice surprising patterns and relationships, and they will want to talk about them.

In this accompanying Teacher's Guide, Christopher Danielson explores deep mathematical ideas such as counting, number language, units, grouping, partitioning, place value, and vocabulary. Throughout, he shares stories and excerpts from real classrooms where he facilitated How Many? discussions. Danielson helps teachers anticipate what students might notice and gives practical suggestions for facilitating rich conversations with students. Danielson's interest in students' ideas is infectious, and readers will soon find themselves seeking out opportunities to ask young mathematicians, "How Many?"