Student Collaboration

From the same Teaching Channel site here's another clip that has some good reminders about ways to establish effective student collaboration.

https://www.teachingchannel.org/video/encourage-student-collaboration

Developing Mathematical Discussion

"The Same or Different: Developing Mathematical Argumentation in Kindergarten."

I came across this clip and thought it highlighted a really good way to start getting children into not only starting to notice similarities and differences but then also being able to express what they notice, explain their thinking and agree or disagree with others.
Lots of thinking going on with one simple activity.