OK, I do see how to do this. I misread the OP as wanting to hook a pair of alligator clips between each bulb and battery, which would not allow for a unique solution.
You’re going to need three batteries, but it’ll be easy from there.
I think for demonstrating circuits to 8-year-olds, Mr. Matthew’s solution would work just fine. So, you can connect green B to red A and make bulb A light up. So what? They’re still learning about completing the circuit to make electric current flow. Connecting green A to red A is the super-simple obvious answer, but there are other ways to make it happen. Does it have to be a unique solution?
Yes it does, for the purpose of the game. The idea is to figure out how to get all three lights lit–finding the correct three pairs of connectors out of eight possibilities. Mr. Matthew’s solution is not an option–it completely defeats the entire point of the whole exercise.
I went ahead and bought two more batteries while I was at the grocery store. Hooked it up as three separate circuits. It works and everything, looks fine… I just didn’t want to have to go to the store LOL
I have some pictures:
(keep in mind that this is my 8 year old son’s project that I’m helping him with…)
http://fff.fathom.org/pages/opalcat/matching-game1.jpg
http://fff.fathom.org/pages/opalcat/matching-game2.jpg
http://fff.fathom.org/pages/opalcat/matching-game-solution.jpg