The idea of “Which One Doesn’t Belong” started with a children’s picture book by Christopher Danielson. Danielson’s book included colorful pages containing thoughtfully designed sets of four shapes. Each of the shapes can be a correct answer to the question, “Which one doesn’t belong?”- Because all of their answers are right answers, students naturally shift their focus to justifications and arguments based on the shapes’ geometric properties.

Because WODB graphics focus on justification and rich, academic vocabulary, teachers around the world have adopted this activity for use in their classrooms at every grade level. Many use WODB as a warm-up or as an opportunity for a spiral review throughout the year. There are also non-curricular examples (like candy options) that can be used for community-building activities in class.

Here’s an example of a WODB using the actual WODB logo:

A student could feasibly pick any of the four images as the one that “doesn’t belong.” The “Which” is a different font from the other ones. The “One” has a circle when the others have a rectangle. “Doesn’t” is in a different color rectangle, and “Belong” is written in white when everything else is written in black. There are no wrong answers but several ways to justify whichever answer that you pick.

The Task

1. Visit the WODB.CALinks to an external site. website. Click on “Shapes” or “Numbers” and scroll through the many examples that teachers have created and added to the site.

2. Choose an EC-6 grade level that you’re most interested in teaching and then choose a specific math content standard/TEKS (not a process standard). You can access the TEKS for K-6 hereLinks to an external site., or you can use the TEKS Alignment documents from our previous assignment.

3. Create your own WODB four-picture graphic that is aligned to that standard that you chose, and explain why each option could be chosen as the one that doesn’t belong. Use precise, mathematical vocabulary when appropriate. If you need graphics, try this awesome siteLinks to an external site.. *Remember that there is NOT a correct answer. All answers could be correct with justification.

4. Make a Google Slide or PPT Slide that contains your (1)TEKS, your (2)WODB, and your (3)justifications. Upload as a .jpg, .png, or .pdf file.

Here is a middle school example (Yours must be EC-6…I just didn’t want to stifle your creativity, so mine is just outside of your TEKS. I made my graphs with Desmos.):