It has something do do with how powerful they are. (Taken from the TI faq) http://www2.bath.ac.uk/~ch6sjb/tifaq/tifaqq2.htm#2.20 Jack TK Pyromaniac wrote: > Why are the calculators called 80,82 etc? Also why is the the 73 called > that when it seems considerably better than the 80, so why is the number > lower? > --Michael