There was some serious brainpower at work at UC Berkeley this weekend, more than usual. About 400 students from around the Bay Area gathered to unravel skull busters at the annual Julia Robinson Mathematics Festival.

Joshua Zucker from the Mathematical Sciences Research Institute said, "The chocolate candies are all about logic puzzles, it's basically the same kind of proofs you would do in geometry class except instead of triangles you get use these little pieces of chocolate. The card tricks are all about patterns and arithmetic, but instead of the patterns be a bunch of additions, they are about some magic answer coming at the end."

The festival is named after a former Cal math teacher who is famous for her work in solving Hilbert's Tenth Problem. It's considered one of the most important math problems of the 20th century.