Berkshire Hathaway founder Warren Buffett, who has famously pledged to give away almost all of his $53 billion fortune, recently launched an online course to show students how to give effectively. At the end of the first “Giving with Purpose” class, which is modeled on a course taught at more than 30 universities, students were able to choose a charity that would receive a $100,000 donation from Buffett’s sister.