Report - Summarize a detail field created by query

I have a simple calculation created in a query which operates as expected. I am trying to then Summarize a report group of items which use this calculation.
After trying numerous methods - I just cannot get any answer.
I have attached images of the actual work.

Please be patient. I have used Alpha 5 for 20 years, and am new to how Libra operates. (Truth is I retired and cannot afford Alpha anymore! )
Thanks for you help.

OH - How the heck do you add an attachment here???


Possibly what you want is on this post → How do I add a sub total to a base report?

There is an upload icon on the toolbar.