Brand:  Casio  
Model:  fx100  
Type:  Scientific calculator  
Batteries:  AA x 2  
Lifetime: 
Introduced: unknown Terminated: unknown 

Notes: 
This calculator is very similar to the Casio fx82, with
the following differences, a bigger display with more digits, SCI,
NORM and ENG modes, rounding, random number generation and a
fraction key. Also functionally very similar to the Casio fx350,
which has less digits but does hyperbolic trigonometric
operations.
This calculator (as do many other Casio scientific calculators) uses one and the same key for both the constant π as well as exponents. This works as follows. When you first enter digits, the "EXP"key will enable you to enter the numbers exponent, otherwise it will enter the constant π.

Picture: 
©2009 Ernst Mulder