Calculator tricks and baking cakes - how two female mathematicians help people have fun with maths.

Sara Santos engages the unsuspecting public in maths through a kind of street performance. Originally from Portugal, Sara now runs a company called Maths Busking in the UK, and tours festivals, schools and corporate events wearing a yellow top hat and doing maths for people's amusement. Her 'tricks' include tying people up with ropes and guessing their birthdays. Sara says the idea that only very clever people are good at maths is rubbish; anyone can do it.

(L) Image and credit: Eugenia Cheng