We dig unique clocks. But if you're not a rocket surgeon, you might need an interpreter to decipher the mathematical marks on this wall clock's face. (Or you can click "read more" and check out our cheat sheet!)

Instead of numbers on this clock's face—you know, like one through 12?— all you get is mathematical notations. You'll sharpen up your useless calculus skills *fast* when you need to know the time.

Ok, so it's no different than telling time on a clock without numbers at all, but the Geek Clock from Uncommon Goods makes a pretty geeky statement. With a schoolyard black-and-white clock style, it will fit in any room, anywhere.

And if you're just a NASA wannabe, then you're in the clear. You'll get a cheat sheet with the clock when it's shipped—or check out the explanations below. It's $25 from Uncommon Goods.

(Brick wall image: Flickr user SnaPsi Сталкер under license from Creative Commons.)

**Geek Clock Cheat Sheet:**

- Legendre's constant is a mathematical constant occurring in a formula conjectured by Adrien-Marie Legendre to capture the asymptotic behavior of the prime-counting function. Its value is now known to be exactly 1.
- A joke in the math world: An infinite number of mathematicians walk into a bar. The first one orders a beer. The second orders half a beer. The third, a quarter of a beer. The bartender says, "You're all idiots," and pours two beers.
- A unicode character XML "numeric character reference."
- Modular arithmetic, also known as clock arithmetic, is a system of arithmetic for integers, where numbers "wrap around" after they reach a certain value. The modular multiplicative inverse of 2 (mod 7) is the integer /a/ such that 2*/a/ is congruent to 1 modulo 7.
- The Golden Mean...reworked a little.
- Three factorial (3*2*1=6)
- A repeating decimal that is proven to be exactly equal to 7 with Cauchy's Convergence Test.
- Graphical representation of binary code.
- An example of a base-4 number, which uses the digits 0, 1, 2 and 3 to represent any real number.
- A Binomial Coefficient, also known as the choose function. 5 choose 2 is equal to 5! divided by (2!*(5-2)!).
- A hexadecimal, or base-16, number.
- A radical