>> ^brycewi19:

That's an absolute thing of mechanical beauty.
Too bad it seems limited to just the multiplication function.


It can very obviously do addition. Every crank adds the number on the side to the number on the top, so just by changing the side between cranks, you've got an adding machine.

Less obvious is subtraction, not shown here. The hand crank on top pops up for subtraction. There's a red or silver ring on the crank that's exposed to make it obvious which mode you're in. Doing this engages an alternate gear set causing the number on the side to be subtracted from the total rather than added.

Multiplication, as demonstrated, is just adding repeatedly.

Division can be done by clever use of multiplication and subtraction. See http://www.isi.edu/~finn/curta/curta.html.

See the following video for a demonstration (but with no real explanation) of finding a square root:
http://www.youtube.com/watch?v=haaCoVrGd6k

It'll never replace the abacus, of which there is now a virtual version:

http://www.coolmath4kids.com/calculators/abacus/

Nevermind, there's a virtual Curta too! Damned technology moves so fast!

http://www.vcalc.net/curta_simulator_en.htm

Is that a curta in your pocket or are you just happy to see me?

Seriously tho .. incredible device.

That's pretty awesome, but its no Curta