The following settings are important for various built-in conversions to work correctly, e.g. to show money values as a percentage (need percent basis), show per unit aggregation options, currency conversions.
Therefore the following steps are recommended in a Datamart:
Mark the per unit basis for the quantity/volume field.
Distinguish if the data is extended or per unit amounts and mark them correctly (see an example of these two options).
Mark the percent basis (recommended to do it based on a list price, not an invoice price as it treats on and off invoice discounts the same).
Make sure the data types are correct. (For example, a Text field containing currency makes no sense. The field type must be set to Currency for the application to handle the data correctly.)
For more details on Datamart fields see Datamarts.