My DD9's school use this as a method of stretching her (with our agreement) and it is working really well.
However it is not all the time (once a week at the moment) and she has one to one time with the teacher to discuss what she wants to teach the class, how she will approach it, what her plans are for particular children in her class with learning difficulties etc.. The teacher is obviously present at the back throughout the lesson, then they debrief after on how it went.
It makes DD think about things in more depth and have better appreciation and understanding of how her peers think.
The other kids also like it as she puts lots of effort into being creative (and often lessons seem to involve chocolate!) and sometimes it is easier for them to understand something from someone who has only recently learnt about it themselves, plus they will ask her in the playground to teach them more!
Admittedly she does not learn much more about the particular topic, but she learns an awful lot about people and communication and the process of learning itself which I feel is more valuable to her.
G
