It's refreshing to see a TV series that's not all about doctors, lawyers, politicians, or a combination thereof. And it's also nice to see that certain characters' nerdiness is not objectified as an easy target for humor as in a few other TV programs. Even though the technical details are glossed over for the sake of maintaining the abstraction barrier (and for having commercial breaks), the writers have done an overall good job in presenting said technical details.
The premise is using mathematical techniques to solve crimes, but the show is not just about math -- the characterization and relationships among the characters bring life to the math and the science. As the seasons progressed, the audience can see how the characters develop, how they gain wisdom (or cynicism), and how their relationships grow.
Charlie starts out with a sheltered, academic-brand naïveté that metamorphoses into confidence, social grace, and some cynicism.
Don learns that he has to let go sometimes and trust his team more.
David grows from a rookie agent to one who's capable of leading a team of his own.
Colby has his share of issues after serving in Afghanistan, but he eventually overcomes them in his own ways.
Megan's experience with some cases eventually makes her leave the FBI team... Larry's space trip expands his spiritual existence, and their relationship opens up both their world.
* * * * * * * * * * * * *
(1) The Eppes
He's responsible, dutiful, dependable, loyal to his family and colleagues, though he gets suspicious easily with a history of commitment issues in romantic relationships. It's not clear why he has trouble trusting others, but it's sometimes an asset, if not an occupational hazard, of working in law enforcement.
In Season 2, it was revealed that Don always had a knack for policing ever since his first game of "cops 'n robbers".
His first appearance captures his essence in a rather flashy way -- driving around in an electric car around Cal Sci campus. (LOLrioKart, anyone?) Typical portrayal of a nerdy character who likes to think about and play with concepts, mathematical abstractions, their applications... and occasionally their physical manifestations in the form of Mythbusters-style experimentation.
1.3 Sibling rivalry
A recurring theme is the rivalry between Charlie and Don. Charlie is five years younger but attends school in the same class year as Don. That creates lots of issues for both of them, especially in high school. Wanting to ask the same girl out to prom was just the tip of the highlighter. (Don got the girl, not surprisingly.) Charlie constantly felt awkward and Don constantly felt like the "stupid one" next to Charlie.
Don felt like he had to compete for parental attention because Charlie needed extra attending to from skipping five grades (the non-academic aspects of life). Charlie, on the hand, wanted to be popular like Don or at least socially accepted.
Earlier in the series, it is apparent that this tension replayed itself numerous times throughout the boys' school years. It has forced Don to be more independent than otherwise, because he perceives that he can never ask anyone for help and has to take care of everything himself.
For what it's worth, had Charlie and Don not worked on cases together, they might have remained one of the "distant" sibling pairs. Though according to their father Alan, Don is always protective of Charlie and Charlie looks up to Don, even though neither of them likes to admit it. This dynamic is central to the plot as Charlie gets more involved with Don's FBI cases. Their relationship becomes more collaborative.
Alan is the epitome of a supportive father. He always shares his wisdom whenever he sees either Don or Charlie in a quandary, whether it be work or relationship problems. To invoke an analogy, Alan is like the Obi-Wan Kanobi for the two young and headstrong Jedi knights. He keeps the brothers together, especially after his wife Margaret passed away (1~2 years before the series begins).
It can be inferred that the Eppes brothers were close to their mom, especially Charlie. Her presence has an overarching bond for the Eppes, as evident in a few Season 2 episodes. The literary analyst in me says that she's a plot device for the purpose of illuminating certain aspects of the brothers... but this overarching effect works very well in softening the otherwise tough-guy atmosphere of the series.
Charlie and Alan live in the same house -- at one point the ownership technically transferred from Alan to Charlie after Charlie placed an anonymous offer to buy the house when Alan put it on sale. And even though Don has his own apartment, he comes by all the time. During one episode where an ATF agent is suspected of committing suicide, Charlie runs the math model he devised to analyze Don's suicide risk -- and concluded he'll be fine mainly because of "strong ties to family". It's heartwarming to see a close-knit family (on TV no less... quite rare these days) that gets along so well despite everything.
(2) Prof. Amita Ramanujan
I was initially skeptical about this role of a hyper-intelligent and beautiful math geek... ingrained stereotypes die hard, as the simultaneous occurrence of desirable traits from these disparate fields is quite rare. I mean, when one thinks of someone who built a working computer from scratch at age 13, what kind of image comes to mind? ... Yes, most likely someone like Napoleon Dynamite.
Somehow Amita does not end up being as well-developed as she could have been. Maybe because she's treated as an "associate" of Charlie. The only scenes where the audience gets a deeper glimpse at her character are where (1) she interacts with an Indian girl forced to become an organ donor on the black market, (2) she objects to her department's decision to take a grant from a pharmaceutical company with a record of shady practices in the 3rd-world, and (3) her getting kidnapped by a domestic radical.
In (1) and (2) we see her generous humanitarian side, and in (3) we see her strength of character as well as vulnerability, albeit in the form of her connection to Charlie. It is unfortunate that the audience doesn't get to see her as much as an independent character as Megan is, perhaps. Her role is more like an extension of Charlie, initially the advisor-advisee relationship they started out in the beginning of the series. The whole iffy-taboo of "dating your TA". Although they do wait until after Charlie's not her thesis advisor anymore to officially start dating.
In any event, it's nice to have such a stereotype-defying character, even if the acting is somewhat awkward at times. Amita has opened up Charlie's world to more than math, despite their disastrous first date where they decide not to talk about work (i.e. math) and end up unable to talk about anything else!
(3) Prof. Larry Fleinhardt
He has the best lines. Mostly with cosmological and/or philosophical metaphors about life. Larry is the most neotenous character in this series, even more than Charlie, in the later seasons. He asks many questions, experiments with ideas, and is always filled with awe much like a child -- aside from his knowledge in astrophysics.
He likes to explore the universe intellectually, with an enviable ability to detach himself from worldliness. Such as not having a house (he camps out in the steam tunnel of Cal Sci). Or a cellphone (until he accepts a space mission from NASA and has to get one for convenience). Well, the spirit is enviable, even if the consequences are not so practical... but hey, it's TV.
Larry is a central element in the series because he has such a unique temperament. He infuses an aura of peacefulness with his philosophizing and child-like wonderment, and this adds a special texture to the otherwise tough-guy fast-paced style of most TV crime series (except Monk!)
It was a sad moment when he left Numb3rs, because after that the plot has fallen into the usual sarcasm-laced matter-of-fact wisecrack dialogues with minimal character development. Although by Season 6, all the characters are pretty much developed anyway...
3.1 Relationship with Charlie
They go waaay back when Charlie begins university at age 14. :-P Larry is a trusted mentor, and later a colleague and friend. A favorite scene is when Charlie calls NASA to vouch for Larry's capability to participate in the space mission, because NASA found out that Larry has been living in the steam tunnels. Even though Charlie doesn't want Larry to leave for 6 months, he decides to help Larry achieve his dream, just as how Larry has helped him achieve his.
Larry is the Yoda of this series. He gives Charlie the right hints at the right times with a slightly manic inflection. Although his grammar is more conventional, he has quirks like a predilection for white foods (which may suggest an OCD tendency... then again, intellectuals often have this tendency or else they would not be intellectuals.)
3.2 Relationship with Megan
When I first started watching Numb3rs (Season 3 or so), I couldn't fathom how Larry ended up with Megan. But when I watched all the episodes in order from Season 1, I found out why. And they've become one of my favorite couples (perhaps even more than Charlie and Amita :-P).