Lens sizes equivalent 35mm film to digital lens sizes?

Just purchased a Nikon D3100 fitted with the 18-55 lens, the camera data states that this equivalent to a 27-82.5 lens (35mm).  I have a number of old lenses from my old nikon 35mm a 24mm, 35mm, 50mm and 105mm.  So I presume that these lenses will be of a different value than the 35mm size?  If so what sizes are they equivalent to digitally?