Thanks everyone! I have finally managed to get it to work using the following:

var oppo_soscollaboration = crm.fields('oppo_soscollaboration').value();

var oppo_soscrta = crm.fields('oppo_soscrta').value();

var oppo_sosvalue = crm.fields('oppo_sosvalue').value();

var oppo_sosvision = crm.fields('oppo_sosvision').value();

var oppo_sospain = crm.fields('oppo_sospain').value();

var oppo_sospower = crm.fields('oppo_sospower').value();

var thetotal = parseFloat(oppo_soscollaboration) + parseFloat(oppo_soscrta) + parseFloat(oppo_sosvalue) + parseFloat(oppo_sosvision) + parseFloat(oppo_sospain) + parseFloat(oppo_sospower);

crm.fields('oppo_sostotal').value(thetotal);

Does this script get placed in the custom content of the screen or on the create script of the fields involved.

Trying to determine why I cannot get some calculated fields to work.  Thanks!

This looks like it is using the Client Side API.  So this will have been placed in either the Custom Content (or in a file included in Custom Content) or an onChange() script.

This looks like it is using the Client Side API.  So this will have been placed in either the Custom Content (or in a file included in Custom Content) or an onChange() script.