CASIO fx‑350


Brand: CASIO
Model: fx-350
Type: Scientific calculator
Picture: CASIO fx-350
Batteries: CR 2025
Lifetime: Introduced: ca. 1980
Terminated: unknown
Notes: This is a scientific calculator similar to the other CASIO models. This one however had one big advantage: the Fraction-key. With this key it was possible to input fractions, and fractions stay fractions as long as you perform a particular subset of operations on them.

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.

When I got this calculator it was broken. Literally, the PCB was in halves. I plated them together and fixed the missing print tracks using coil-wire. And it still works great.