The expression can
use any arithmetic operations (+ - * / %), arithmetic functions, or aggregation
functions. The arithmetic functions include all those supported by the
JavaScript Math class.
As an example, say you want to calculate the volume on a form that includes the Height,
Width, and Length fields. You could perform this calculation using this
expression:
"Height * Width * Length"
Since this expression is defined as a setting on the Volume
field, the result displays as the value for that field.