Numberphile is a maths youtube channel, but with over a million subscribers it features some of the most popular videos on the internet. Go on, ask your students, they will have heard of it. Run by Brady Haran, it stars James Grime and Matt Parker.
To recreate the experience of a Numberphile video, James and Matt will take maths suggestions from the audience and talk about them in front of a camera while writing on brown paper.
In other words: it is an energetic maths improvisations session even people who have never seen Numberphile will enjoy.