Sumation between two field

I add two fields and want to see the sum in a other field. How is it possible?

Dear Simit,

Here is our syntax guide.

http://support.mysurvey.solutions/customer/en/portal/articles/2537453-syntax-guide-operators?b_id=12728

Survey Solutions Team support

Calculated results can be displayed as part of the question text or static text if the calculated variable name is included between two % signs. For example:

the sum is: %mysum%

See also the “Public example User questions and common patterns” questionnaire, e.g. Livestock section and many others there.

Best, Sergiy