Bitcoins are mined utilizing a cryptographic algorithm referred to as SHA-256. This algorithm is easy sufficient to be executed with pencil and paper, as I present on this video. Not surprisingly, it is a completely impractical technique to mine. One spherical of the algorithm takes 16 minutes, 45 seconds which works out to a hash fee of 0.67 hashes per day.
For particulars, see http://righto.com/sha