Be it from George Orwell's novel 1984, Soviet propaganda or the Radiohead song, most people are acquainted with the (false) equation 2+2=5. Apart from its use to criticize autocratic systems and to encourage workers, one can also look at the equation from a mathematical point of view.

Whether you merely want to hint at the rounding of numbers common among engineers or the problem of significance when it comes to decimals, this mug is the ideal tool for you. And who knows, maybe the conversation started by the joke might turn into a fully-fledged mathematical discussion ;). Well, you never know!