CASIO FX 991 ES PLUS SCIENTIFIC CALCULATOR

1. **Power On/Off**: Press the “ON” button to turn on the calculator. To power it off, press the “SHIFT” key followed by the “AC” key.

2. **Numeric Entry and Operations**: Use the keypad to input numbers and perform mathematical operations. The FX 991 ES Plus supports basic arithmetic operations such as addition (+), subtraction (-), multiplication (×), and division (÷). Enter the numbers followed by the desired operation, then press the “=” button to display the result.

3. **Scientific Functions**: Access scientific functions by pressing the appropriate buttons on the calculator. These functions include trigonometric functions like sine (sin), cosine (cos), tangent (tan), logarithms (log), exponentials (exp), and more. Use the “SHIFT” button to access secondary functions printed above each key.

4. **Clearing**: Correct errors or clear the display by using the “DEL” key to delete the last entry, or the “SHIFT” key followed by the “AC” key to clear the entire display.

5. **Memory Functions**: Utilize memory functions to store and recall numbers. Use “M+” to add the current number to memory, “M-” to subtract from memory, “MR” to recall the number from memory, and “MC” to clear memory.

By following these steps, you can effectively use the Casio FX 991 ES Plus Scientific Calculator to perform various mathematical calculations and utilize its advanced scientific functions.