This talk is about the world's most popular programming language...Java? Python? COBOL? No... Excel! Excel somehow hits the sweet spot between being powerful enough to run entire domains like finance and insurance, but also easy enough to attract a huge audience. Why is that? In this talk we'll explore some of the mechanisms that make spreadsheets so powerful, while implementing a few interesting mathematical problems in spreadsheets. While doing that, you might learn some (functional) programming concepts too, as we'll talk about sorting, dynamic programming and lambdas.