This document is the user manual for Casio fx-991ES calculator, providing information on the calculator's key functions, usage instructions, and safety precautions.
This manual explains how to set up and operate the Casio fx-991ES scientific calculator, covering key functions, mode selection, and input methods. It also includes safety precautions, battery handling, and maintenance tips.
Technical specifications such as power source, battery life, operating temperature, dimensions, and weight are listed, along with troubleshooting steps for common errors and guidance on adjusting display contrast. This manual is written in Chinese.
| Power source | Solar cell built‑in + G13 (LR44) button battery |
|---|---|
| Battery life | Approximately 3 years (1 hour use per day) |
| Operating temperature | 0 °C to 40 °C |
| Dimensions | 12.2 mm × 80 mm × 161 mm (H × W × L) |
| Weight | Approximately 105 g (including battery) |
The battery should be replaced at least every three years.
Press the SETUP key, then use the d and e keys to adjust the contrast, and confirm with the A key.