He's also the author of Shape: The Hidden Geometry of Information, Biology, Strategy, Democracy, and Everything Else. And now Ellenberg is a Guggenheim Fellow, a Harvard graduate, and a professor of mathematics at the University of Wisconsin-Madison. He scored a perfect 800 on the math portion of his college entrance exams - the SAT's - at the age of 12. It's a party trick he used to do in college. Give Jordan Ellenberg a number and he'll tell you its square root.