• Alex Box

Which One Doesn't Belong? for Fractions

Updated: Jun 5

Which one doesn’t belong? The top left, top right, bottom left or bottom right? What's your argument for why?


What about the other quadrants? What arguments can be found for those?

Which One Doesn't Belong? (WODB?) is one of my favourite maths talk routines. I love how it creates an authentic and engaging context for thinking about and making sense of mathematical ideas.


Accessible to all, WODB? is a great routine for the whole class and is great 'bang for buck'. In as little as 5 to 10 minutes, the group engages in a range of thinking - comparing and contrasting, constructing arguments, communicating reasoning and considering other perspectives. I highly recommend it.


The visuals are designed to ensure at least one argument, often multiple, can be found for each quadrant. This helps create mathematical moments where 'the answer' cannot be quickly, easily or definitively found. To be left hanging with some uncertainty, or curiosity about 'what else' there is to notice, is a good thing - it helps build to a community of mathematical thinkers.

To learn more about WODB and how to run it, check out this nice and succinct description by The Learning Space.


You can also read my earlier post Connecting maths and people through WODB? .

New Fraction Prompts

Since Michaela Epstein's Four Powerful Ideas for Learning Fractions, I’ve developed some new WODB designs to spark conversations around these ideas. The above is just one of eight new images - please feel free to make use of them in the classroom.


You can access these files in this google drive folder.


If you use any of these visuals with the students you work with, I’d love to know:

  1. Which prompt(s) did you use?

  2. What mathematical ideas came out in the discussion?

  3. Did anything surprise you?

If you’re looking for more ways to help students see fractions in a new light,

consider joining us at the next online Maths Teacher Circle on April 15.

Learn more and secure your spot here.


To have the latest tasks, tools and tips delivered straight to your inbox,

join the Maths Teacher Circles community.





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