''Rescue Me'' actress trades fires for nerd-speak -- Diane Farr turns up the heat on CBS math drama ''Numb3rs''

If a person is the sum of her experiences, then Diane Farr is one confusing equation. The onetime model was crowned Miss New York at age 19 before going off to England to study acting. Then in 1997, back in the States, she simultaneously managed an L.A. eatery owned by Christina Applegate and worked as a drama teacher at a maximum-security men’s prison in California. (”It was like sending Barbie into hell!” Farr recalls.) In 1998, Barbie left the Big House and won the cohost role on MTV’s late-night call-in show Loveline.

So it’s only natural that such a complex set of variables would land Farr on CBS’ second-year math drama, Numb3rs (Fridays at 10 p.m.), playing an FBI behaviorist. ”It’s been so fantastic,” says the actress, who also had a recurring role on The WB’s Roswell. ”Megan is a bit of a cowboy. She has a master’s degree, comes from money, and wears a fantastic suit but still likes carrying a gun. It’s high-end adrenaline.”

The gig is a nice follow-up to the working-class adrenaline Farr had flowing through her veins as Rescue Me‘s tart-tongued, affirmative-action-hire firefighter Laura Miles. While she says she’ll miss the station house (Miles bid the guys farewell in the FX drama’s Sept. 13 finale) and costar Denis Leary (”my closest girlfriend,” Farr says of Leary. ”You can discuss colors of curtains with him”), the role took a toll. The New York-based show (along with her stint on Leary’s NYC-based The Job before it) kept her away from her L.A. home for nearly five years, and she had to sport firefighting gear that weighed — here’s another number — 65 lbs. ”For the first year, I just wanted to keep up,” Farr says. ”By the second year I was going to the chiropractor and the acupuncturist, so I knew it was going to be short-lived.”

Farr needed a very different kind of professional help for her new role: The vernacular on Numb3rs can be so difficult that she hired a coach to learn nerd-speak. Another skill to add to the résumé? ”I saw a bumper sticker when I was a little girl that said, ‘The player who ends up with the most toys, wins,”’ Farr says. ”And I’ve taken it to, ‘People who’ve had the most bizarre set of experiences win!”’