Brand: CASIO
Model: COLLEGE fx-80
Type: Scientific calculator
Picture: CASIO fx-82
Batteries: AA x 2
Lifetime: Introduced: unknown
Terminated: unknown
Notes: Predecessor of the CASIO fx-82 and all its descendants. The standard of high school calculators when I was still in high school. This one, together with the CASIO fx-81 were actually the most popular calculators when I myself was still in high school. The CASIO fx-81 was the cheeper one because it officially doesn't support statistical functions. That was a little trick of CASIO because these two calculators were basically the same. To enter the statistical mode on the CASIO fx-80 one has to press "INV" "D·R·G". When these keys are pressed on the CASIO fx-81 (I am still looking for one!) the display shows "ERROR" at the position where the CASIO fx-81 shows "sd". However, all statistical functions are there, it's just a matter of remembering the CASIO fx-80's key layout! The "ERROR" notification is just there to scare you. I was quite surprised when I found out at the time.

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.

It is a robust and solid calculator for school usage. The fact that it uses ordinary (AA) batteries that can last for years is also a big advantage.