This action configuration will help you if you need to sum values.
The main thing to note here, is that with the Process using XSLT option we can use some standard XSLT functions. So you should be aware of this when you use that option. This could solve some functions that we need and that are not available as inline functions.
Fernando Hunth | firstname.lastname@example.org
Nintex Workflow 2013
Nintex Workflow 2010
SharePoint Server 2013
SharePoint Server 2010
|Adding functions to Nintex Workflows with XLST transformations|