From LimeSurvey Manual

Equation (equation)


The result of the expression you type here will be stored in the response table and NOT the result(s) of the expressions typed in the question textbox. For example, you may want to display several expressions in the question textbox to display the respondents some statistics about herself. However, if you wish to store something different at the same time, then type the desired expression in this field.

This equation is used for all language.

Valid values