Small history of Computation. From Abacus, Slide Rules to Electronic Calculators.

Brian Beckman A Brief History of Computing.

I enjoyed this very instructional video produced by Microsoft Channel 9.

Brian Beckman: A Brief History of Computing

The video is about different instruments use for computations from manual to mechanical to electronic devices invented with the purpose of making numerical computation easier to do it is very interesting to see.

In the video there is a full explanation on how to use the Curta you may be able to practice what you learn with this simulation  Flash Demo of the Curta.

To see the video is good to have the SilverLigth Video plugging by Microsoft.