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Casio fx-21

Casio fx-21

The Casio fx-21 is a scientific calculator with 8 digits precision and algebraic logic. It has 30 functions, 35 keys, and a VFD (vacuum fluorescent) display. The power source is 2xAA. The calculator was manufactured in Japan. Note: Boots 424; MBO fx-21 picture credit: Enrique García Simón

Facts at a glance:

FeatureValue
TypeScientific
Functions30
Keys35
Precision8
LogicAlgebraic
Display typeVFD
Length145mm
Width84mm
Thickness25mm
Power Source2xAA
CountryJapan
Year introduced1977
Year discontinued1977

User Manual

You can download the Casio fx-21 manual from this external link.

Replacements:

If you have a Casio fx-21 that is no longer working, you can first try replacing the 2xAA batteries. If that doesn't solve the problem, then you can consider replacing the calculator with a modern equivalent. We suggest the following current model as a replacement:

See other calculators by Casio