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 batteries. The calculator was manufactured in Japan. Note: Boots 424; MBO fx-21 picture credit: Enrique García Simón
Facts at a glance:
| Feature | Value |
|---|---|
| Type | Scientific |
| Functions | 30 |
| Keys | 35 |
| Precision | 8 |
| Logic | Algebraic |
| Display type | VFD |
| Length | 145mm |
| Width | 84mm |
| Thickness | 25mm |
| Power Source | 2xAA batteries |
| Country | Japan |
| Year introduced | 1977 |
| Year discontinued | 1977 |
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: