Hello Mathew -
I'm not a Cube's pro myself but the few times I have had to dig in on them, I have utilized the examples found on the adventureworks examples here - Understanding Functional Differences Between OLAP and Relational Data Source Connections | Tableau Software
If you have a MSAS cube setup with the demo database 'Adventureworks" - then download this example and point it towards your sample. There are lots of examples in the workbook.
You have to redesign your cube. All numeric values ie. QTYs and Units should be defined as measures.