Everyone agreed on the first step: Solve inside the parentheses, for 2+2=4. But after that, people split down two paths. Some multiplied first, while others divided, leading to different answers—1 and ...

Every few months, the Internet eats itself over some kind of viral riddle or illusion, each more infuriating than the last. And so, like clockwork, this maddening math problem has gone viral, ...