Combinatorics is a fancy word for counting. Doing really big problems by the partial products method gets really cumbersome and no one actually does it. Don’t try to do this chapter if you don’t have ...

There is no shortage of popular books and lectures on math—but they can only teach us so much. Mathematics has long been presented as a sanctuary from confusion and doubt, a place to go in search of ...

At 21, Ashwin Sah has produced a body of work that senior mathematicians say is nearly unprecedented for a college student. The proof joined a long list of mathematical results that Sah, who turned 21 ...