"We all use math every day", goes the opening line in the first season. Especially Charlie Epps. His brother Don, an FBI agent, thought that the FBI could use someone like Charlie, who's highly skilled in mathematics. NUMB3RS shows how math is sometimes used to solve crimes. In one episode, for example, when a college student died it was at first thought to be a suicide. But when Charlie did all his calculations it was concluded that the death happened because of some faults with a building. In what turned out to be the final episode mathematics even enabled Don to find and get back his gun! While some may find the show nerdy, everyone can benefit from watching the show. While parts of each episode will go over viewers' heads unless they've taken up serious study of mathematics, they'll see nevertheless the role math sometimes plays in solving crimes. As for the violence, while it's more intense than that in crime dramas of the 70s or 80s, it isn't really any more intense here than in many other crime dramas today, and it only lasts briefly in this show. Certainly it isn't anything that teens haven't already seen. (Even if parents disapprove of or forbid such shows, teens hear about them from kids at school or family gatherings or perhaps even from teachers.) In summary, I'd highly recommend NUMB3RS, as it introduces viewers a new way of thinking about math.
But don't get the wrong idea. In October of 2005, at the start of the 2nd season, David Krumholtz (Charlie) told TV Guide that children as young as 6 were watching. NUMB3RS isn't for kids that young! Kids at that age should be learning about numbers from SESAME STREET or CAPTAIN KANGAROO! I'd give this show a red light for 11 and under, a yellow light for 12-14 and a green light for 15 and up.