This is a user manual for the Casio fx-991ES calculator, which introduces the calculator's functions, operating methods and usage precautions
This manual explains how to set up and operate the Casio fx-991ES scientific calculator, covering key functions, display modes, and menu navigation. It includes safety precautions, battery handling, and initialization steps to ensure reliable use.
Technical details such as power specifications, dimensions, and battery type are listed, along with guidance on adjusting contrast, using different calculation modes, and maintaining the device over its lifespan. This manual is written in Chinese.
| Battery type | G13 (LR44) x 1 |
|---|---|
| Battery life | Approximately 3 years (based on 1 hour daily use) |
| Operating temperature | 0 °C to 40 °C |
| Dimensions (H × W × D) | 12.2 mm × 8.0 mm × 16.1 mm |
| Weight | 105 g (including battery) |
The battery should be replaced at least every three years to avoid leakage and loss of data.
It uses a single G13 (LR44) button cell battery.
The calculator measures 12.2 mm high, 8.0 mm wide, and 16.1 mm deep.