I was just simply showing my girls (8 and 6) how electricity works the other night -- I had taken a small electric bulb out of an old stereo system. The bult still had the wires connected to it so I touched the wires to the + and - sides of a 9v. battery.
The bulb lit up and I was able to show the girls how electricity "wants" to travel around a circuit and how the electricity lights the little bulb.
a small variation you could use for a science project might be to use different batteries to see how the light is stronger or weaker depending on the amount of electricity.
It was cool and typical of how learning should work.
We took the snap electronics kit to the youngest grandkids birthday party last sunday night at a pizza place.
they are still to young to use it, plus grandma likes the idea of using it for bait to have them come by *grin*
however my sons, 22-26 played with it all night.
the center of attention was the motor and heliocopter rotor.