Casio DH-12ET Desktop Calculator User Manual

Introduction

This manual provides detailed instructions for the proper use and maintenance of your Casio DH-12ET Desktop Calculator. Please read this manual thoroughly before using the calculator to ensure optimal performance and longevity.

Figure 1: Front view of the Casio DH-12ET Desktop Calculator, showing the display and key layout.

Product Features

The Casio DH-12ET is a versatile 12-digit desktop calculator designed for various business and personal calculations. Key features include:

• 12-Digit LCD Display: Clear display with calculation command indicators and thousands separators.
• Tax Calculation: Dedicated functions for easy and quick calculation of tax additions or subtractions.
• Currency Conversion: Ability to convert amounts between two currencies after setting an exchange rate.
• Professional Percentage Calculation: Determine percentage increase and decrease with separate display of calculated values.
• Mark Up Function: Quickly determine margins and markups.
• Square Root Function: Calculate square roots.
• Sign Change (+/-): Easily switch between positive and negative values.
• Total Sum Memory (GT): Automatically stores the sum of all calculation results.
• 3-Key Memory: Independent memory functions (M+, M-, MRC) for storing and recalling values.
• Solar/Battery Operated: Dual power source for reliable operation.
• Automatic Power Off: Conserves battery life by shutting down after 6 minutes of inactivity.
• Memory Protection Battery: Retains stored data (e.g., currency rates, tax rates) during power loss or battery change.
• Rubber Feet: Provides stability on surfaces.

Setup

Power Supply

The Casio DH-12ET calculator operates on a dual power system: solar power and a single LR44 button cell battery. The solar panel provides power in well-lit environments, while the battery acts as a backup in low light conditions or when the solar power is insufficient. The battery also serves as a memory protection battery.

Battery Installation/Replacement

The calculator comes with one LR44 battery pre-installed. If the display becomes dim or unresponsive in low light, the battery may need replacement.

1. Ensure the calculator is turned OFF.
2. Locate the battery compartment on the back of the calculator.
3. Using a small screwdriver, remove the screw securing the battery compartment cover.
4. Carefully remove the old LR44 battery.
5. Insert a new LR44 battery with the positive (+) side facing upwards.
6. Replace the battery compartment cover and secure it with the screw.

Note: Dispose of used batteries according to local regulations. Do not expose batteries to excessive heat or fire.

Operating Instructions

Basic Calculations

• Addition: Enter first number, press +, enter second number, press =.
• Subtraction: Enter first number, press -, enter second number, press =.
• Multiplication: Enter first number, press x, enter second number, press =.
• Division: Enter first number, press ÷, enter second number, press =.
• Clear Entry: Press C to clear the last entered number.
• All Clear: Press AC to clear all entries and reset the calculator.

Tax Calculation

The calculator allows for easy addition or subtraction of a pre-set tax rate.

1. Setting the Tax Rate:
   • Press AC and hold the % key until "SET" appears on the display.
   • Press TAX RATE (which is the TAX+ key).
   • Enter the desired tax rate (e.g., 8 for 8%).
   • Press % to confirm and save the tax rate.
2. Adding Tax: Enter the amount, then press TAX+. The display will show the amount with tax added.
3. Subtracting Tax: Enter the amount with tax, then press TAX-. The display will show the original amount before tax.

Figure 2: Steps for changing the tax rate on the Casio DH-12ET calculator.

Currency Conversion

The calculator supports conversion between a local currency and a foreign currency (e.g., Euro).

1. Setting the Exchange Rate:
   • Press AC and hold the % key until "SET" appears.
   • Press RATE (which is the Euro key).
   • Enter the exchange rate (e.g., 1.25 if 1 Local unit = 1.25 Euro).
   • Press % to confirm and save the rate.
2. Converting Local to Foreign: Enter the local amount, then press Euro.
3. Converting Foreign to Local: Enter the foreign amount, then press Local.

Percentage Calculations

• Calculate Percentage of a Number: Enter number, press x, enter percentage value, press %. (e.g., 100 x 15 % = 15)
• Add Percentage: Enter number, press +, enter percentage value, press %. (e.g., 100 + 15 % = 115)
• Subtract Percentage: Enter number, press -, enter percentage value, press %. (e.g., 100 - 15 % = 85)

Memory Functions

• M+: Adds the displayed value to the memory.
• M-: Subtracts the displayed value from the memory.
• MRC:
  • Press once to recall the value stored in memory.
  • Press twice to clear the memory (M indicator disappears).
• GT (Grand Total):
  • Automatically accumulates results of calculations (e.g., after pressing = or %).
  • Press GT to display the grand total.
  • Press AC to clear the grand total memory.

Other Functions

• √ (Square Root): Enter a number, then press √ to calculate its square root.
• +/- (Sign Change): Changes the sign of the displayed number from positive to negative or vice versa.
• Decimal Selector (F CUT 5/4, 4 3 2 1 0 ADD2):

  This slider switch controls the decimal point and rounding settings:

  • F (Floating): Decimal point floats, displaying all digits.
  • CUT: Truncates results to the specified number of decimal places.
  • 5/4: Rounds results to the specified number of decimal places (standard rounding).
  • 4, 3, 2, 1, 0: Specifies the number of decimal places (e.g., '2' for two decimal places).
  • ADD2: Automatically adds two decimal places for currency calculations.

Maintenance

Cleaning

To clean the calculator, wipe it gently with a soft, dry cloth. For stubborn dirt, slightly dampen the cloth with water and a mild detergent, then wipe dry immediately. Do not use strong solvents, abrasive cleaners, or spray cleaners directly onto the calculator.

Storage

Store the calculator in a cool, dry place away from direct sunlight, extreme temperatures, and high humidity. If storing for an extended period, it is recommended to remove the battery to prevent leakage.

Troubleshooting

• Display is dim or blank:
  • Ensure the calculator is in a well-lit area for solar power.
  • Check the battery. Replace the LR44 battery if it is depleted.
• Incorrect calculation results:
  • Press AC to clear all previous calculations and memory.
  • Verify the decimal selector switch setting.
  • Check if any memory functions (M, GT) are active and interfering.
• Keys are unresponsive:
  • Ensure the calculator is powered on.
  • Clean around the keys to remove any debris.
  • If the issue persists, try replacing the battery.

Specifications

Figure 3: Side view of the Casio DH-12ET calculator with approximate dimensions.

Warranty and Support

For information regarding warranty coverage, service, or technical support for your Casio DH-12ET Desktop Calculator, please refer to the warranty card included with your product or visit the official Casio website for your region. Contact details for customer service are typically available on the manufacturer's website.

Casio Official Website: www.casio.com