How to Set Decimal Places on an HP 12C
The HP 12C financial calculator makes it easy to make calculations on the fly when trying to determine financial margins. The 12 C model features advanced compatibility with European business calculations as well as American standards for business. If you want to set the decimal places, you must press a certain key combination to access the settings. This combination tells the calculator to set the number of decimal places calculated you want. The calculator, by default, bases itself on two digits after the decimal point for standard monetary work.

Turn on your calculator and press the "f" button.

Press "CLEAR" if you had any data showing on your calculator while it was on.

Press the "REG" button and "f" again.

Press one of the numeric keys to indicate how many decimal places you want your calculator to show data at. This finishes the setting process.