How do you use decimal function on casio hr-8tm?

To use the decimal function on a Casio HR-8TM, first press the "MODE" button to select the appropriate calculation mode. Then, input your numbers and use the decimal point key (usually labeled as ".") to enter decimal values. You can adjust the number of decimal places displayed by pressing the "SET" button followed by the appropriate number key (0-4) to choose the desired decimal settings. Finally, perform your calculations as needed.