How to remove an initial value (0) from a "Numeric Entry" field

update - for those that get into this position (see thread above); don't create text variables as you lose the calc functionality, instead i) create a new numeric field (beside the old one), ii) rename the default variable on it.... this way the numeric variables are maintained in the triggers and it's speedier to rework. If you replace with text fields  you lose the values in the triggers when you rework it. This sounds confusing even as i type it. 

Moral of the story; rename default numeric variables, don't create new (or zero becomes your new best friend)