Help interpreting Google search result

[Tom Zimoski]

I've sent essentially this same message to Google and may one day receive
a reply but I am not optimistic.

While preparing for a beginning internet class we will be offering to the
public I was playing around and came up with these results from Google: 
  
pikachu        about 206,000 hits
pikachu -porn  about 134,000 hits
pikachu porn   about     943 hits  (including www.pokemon.com)

It seems to me that the last two should add up to the first. I know each
number is preceded by "about" but really! There may be something
basic about using Google that I fail to grasp.  Can you help? 

When I do the same searches at http://www.ussc.alltheweb.com/
the numbers are consistent with each other.

pikachu         88,903
pikachu -porn   87,714
pikachu porn     1,189


Tom Zimoski                     Phone: 559-488-2976
Reference Dept.                 Fax:   559-488-6735
Fresno County Library           Email: tzimoski at sjvls.lib.ca.us
2420 Mariposa St.
Fresno, CA  93721
USA