Building formulas
Custom formula fields require additional settings as specified by the Salesforce CRM application, which are carried out using the following actions and steps:
Create the Formula field.
Choose the data type for the field, based on the output of the calculation.
Enter the number of decimal places for currency, number, or percent data types.
Note
The setting for the number of decimal places is ignored for currency fields in multi-currency organizations. Instead, the decimal places for your currency setting apply. Salesforce uses the round-half up, tie-breaking rule for numbers in formula fields. For example, 12.345 becomes 12.35 and -12.345 becomes -12.34.
Click on Next to display the formula creation screen.