Eliminating report results where one field has a null value

I am reporting using a Quantity field from the Opportunity. This field is a number field, and is not a required field. In some opportunities the field is left blank; I want to eliminate these records where the Quantity field is blank from my report but when I filter on the quantity field using "is not null", or "is not in or is not equal to 0" or "is >0", the report never finishes running. 
The value that defaults to the Quantity field for these records in the report if I do NOT try to filter them out is 0.00.

Suggestions?