When working with very large or small numbers, scientific notation is very handy. The calculator will automatically give an answer in scientific notation if the answer cannot be displayed in 10 places.
To have the calculator display ALL numbers in scientific notation, use the
MODE key
It looks like this:
Use the right arrow key to highlight the SCI and
press enter 
Now press 2nd-QUIT keys to return to the home screen.
2. Entering numbers to be displayed as scientific notation
Key in the number, and press
enter: 
The "E" means the X 10 and the 4 is the exponent.
3. Entering numbers already in scientific notation
Enter the
numeric part, press 2nd - , (the EE key) and ENTER.
NEVER use the times key when doing scientific notation.
4. Numbers that are not in correct scientific notation form will be fixed automatically by the calculator.
5. To display a standard numeral given scientific form, change the MODE back to NORMAL, return to the home screen and press ENTER.