Hey there!
I'm using the expression editor to populate a text widget. The expression is substrating two SUM({fieldname}) values.
Expression:

SUM({Cases}) - SUM({Total Cases})
Issue:
When the math calculates to 0 I get a null return meaning nothing displays in my text box. When the math returns 0, I would like to display 0 in the text box.
Am I missing something in the expression editor?