Danica McKellar continues to look amazing! "Forty is the new 25," the former The Wonder Years star says. It sure looks it. McKellar tells me. Actress and math advocate, Danica McKellar returns to Warwick's for her new book, Hot X: Algebra Exposed on Wednesday, August 18th at. Danica Mae McKellar (born January 3, ) is an American actress, mathematics writer, and mathematics (as she has a bachelor's degree in mathematics from UCLA): Math Doesn't Suck, Kiss My Math, Hot X: Algebra Exposed, Girls Get.