10 Child Stars Who Grew Up Just Fine

Danica McKellar
McKellar speaking at the 18th annual LA Times Festival of Books in 2013. © Imeh Akpanudosen/Getty Images for LA Times

Danica McKellar, who played girl-next-door Winnie Cooper on the '80s sitcom "The Wonder Years," has taken some grownup roles (and grownup photos – she posed in her skivvies for Stuff magazine in 2005), but she's best known these days for her math acumen, not an inclination for public scandal.

While McKellar continues to act in her adulthood, these days she's also on a mission to get kids -- and especially young girls -- into math; she's the author of a handful of math books (including "Math Doesn't Suck," "Kiss My Math," "Hot X: Algebra Exposed" and "Girls Get Curves: Geometry Takes Shape!"). And she's qualified: In school, she also co-authored what would become the Chayes-McKellar-Winn Theorem. And her Erdős–Bacon number -- the number of degrees of separation a person has from Hungarian mathematician Paul Erdős in paper authorship plus the number of degrees of separation that person has from Kevin Bacon in acting roles -- is 6.