Teaching children about circuits and the way electricity works is a "tricky business" because it is invisible. Just imagine all eyes are on the teacher as he or she produces for the class what looks like a ping-pong ball and then, with a wave of their hand, the incredible happens! This wonderful white sphere begins to glow red and a bleeping noise is heard. What is it? Could it be "electrickery"! Of course, it is not magic at all... it is science. The secret is that there are two strips of metal on the bottom of the ball, and when the teacher places his or her fingers on both of them, it makes a connection across the skin, the button batteries inside make a small LED light up and a buzzer sound. The toy ball may look like a cheap child's toy but it has a really creative role to play in helping children with their understanding of how electricity works.