OK, this one is called 'Spinning colour wheel'.
It looks like you get some cardboard and draw a circle on it, divide it into six equal segments and colour each one in using different colours, then you thread a piece of string through the middle. So we'd need some string as well. Oh, I didn't know that. What's the principle behind it? Well it's pretty elementary physics, really. It teaches them about how white light or ordinary light is made up. Hmm, well that doesn't sound too bad. Now there's only one more left in this book isn't there? What does that one say? Um, well it's another one where they'd get to make something. Sounds very interesting. You need quite a lot of equipment actually - a hand drill, an old record, a pin or needle, some paper and a bolt. Hmm, go on, what do they have to do?