Building Functions into Formulas
You use the Formula Builder—Function tab to enter functions into freeform formulas.
See About Freeform Formulas.
To build functions into formulas:
Access Formula Builder.
See Using Formula Builder.
Select Function to add functions into the formula.
In Names, select a function.
See Functions Used in Formulas.
Add the function:
In the Names list box, double-click the function.
In the Examples list box, double-click an example to enter the sample syntax, which you can modify.
Click on the Formula text box and manually enter functions.
Click OK.