Increasing math talk

It sometimes takes a while to get kids to feel comfortable talking math.  They can find it hard to defend their answer, use the correct vocabulary, and have confidence in their thinking.

This website might help with that!  It is called Which One Doesn't Belong? , and it follows the idea of the great Sesame Street clip "One of these things isn't like the other..."  The trick is there are many correct answers.  Students choose their reason that one doesn't fit and then defends it to the group.  Others might choose a whole different answer and be able to defend it as well,

There are puzzles on here for K-5.  I think they might make a great opening activity, math station, or small group activity. Can your students make an argument for each of the four numbers?

I'd love to hear how you use it!  If you make new puzzles to use in your classroom, please consider sharing in your grade level folder and/or with me.  People are always looking for new ways to challenge their students.  

Which of these doesn't belong?