(spots vs. stripes)
After doing this for a bit, I made up some categories that were not mutually exclusive. After sorting some animals, I handed one of the girls an animal that could fit into both categories. Now we had a dilemma. I made a big dramatic production of it ("oh, no, what should we do? How can it go into both circles?"). After letting the girls think it over for a bit I came up with a solution - crossing the circles so animals can fit in the intersection if they belong in both circles.
Over the next couple days, we repeated this activity, but with different manipulatives. Initially, I always started with two separate circles and then presented the dilemma of an object that fits into both categories. Soon the girls solved the problem themselves by intersecting the circles..
(round snacks in the green circle, salty snacks in the yellow circle)
(letters with straight lines, curved lines, or both)
After a couple rounds of the Venn Diagram game, the girls started to immediately cross the circles when they made them. Then the challenge was to figure out the categories on their own from a set of objects. They're still working on this type of problem, but it's wonderful to see their logical reasoning skills in action..
(red shapes, circles, red circle in intersection)
(mustaches vs. yellow shirts)
I used all sorts of objects from various games, items around the house, snacks, etc.. for these exercises so it would feel like a new game each time we played. The kids caught on quickly, and I think they'll soon be ready to continue with more Boolean logic (AND / OR / NOT ) and predicate logic (ALL, SOME, NONE) activities that build on these Venn Diagrams. Stay tuned...
UPDATE: I was so inspired by how much my kids enjoyed early math "games" that I created the La La Logic Critical Thinking Curriculum for 3-6 year olds, which includes online brain challenge games, printable worksheets, enrichment activities and more!