On the day I was with this year 2 class they were mid-way through a weather unit. It seemed a good opportunity to combine some art in their study by creating cool and warm magazine collages. I had only just previously spotted some blue/purple/green and red/yellow/orange collages at Riverside Elementary's blog.
As there wasn't time in the day for an entire art lesson this activity became (and worked very well as) a collaborative effort. Initially the collages were started by the fast finishers but then the whole class pitched in to help. The children scoured glossy magazines looking for any suitable colours, cutting them out and sorting them into their appropriate cool or warm group. Other students were busy arranging and pasting the cut-outs down. It was simple, it really underlined the two distinct colour groups to the children and was a great way to utilse some cooperative learning.