You may have You Tube blocked at school or you may just want to look for some useful resources for teaching. Teacher Tube is trying to keep all uploaded videos safe and relevent.
One example could be ’hotmaths’ where pupils can watch worked examples being explained for them.
Well worth a look I’d say but be warned – quite a lot of teachers apparently think that filming powerpoint makes an interesting video! (still may provide some ideas for next years WISCAS)