Math operations and embedded data

Hello
I am sure the answer to this is probably super simple, so allow me to make a fool of myself.

I have an embedded data field called Total and this sums the scores of my questionnaire.
I want to then average that e.g. ${(e://Field/Total)/55}
At the end of the survey I am using piped text to provide participants with their score.
I have searched the community and tried every permutation I can think of (with spaces, without spaces, with and without brackets and more..) and in testing the total score shows up in the dataset and the resulting email, but the calculated average does not.
Glen