As irony would have it, actor David Krumholtz gained celebrity by playing a mathematical genius on the hit CBS procedural, “Numb3rs” (2005- ), even though in real life his math skills have been mediocre at best—a 520 on his SATs after heavy studying was a high watermark. Coming from a long line of failed television series, Krumholtz has been surprised by and appreciative of the success of the crime drama that became the most watched show on Friday nights in 2005. Though his success came at a young age—he was only 26 when the show first aired—Krumholtz had toiled in the business since he was