I need a fillable form to not have any data in the calculation fields before starting the form.

I am creating a fillable form that has several calculations in it. Some are simple calculations of sum = adding the column, where others are custom calculations. 

As it sits now, the blank form has ‘0’s’ in all of the fields with calculations. How do I keep all of the fields blank? The form needs to be printed blank for the one who still use paper copies. 

Thanks in advance