Calculated Measures issue

Summary:

Calculated Measures when null value exists

Content (required):

I have two measure. The one being invoice amount and the other being invoice paid amount. For both of these there are some null values. So in my analysis I have set a conditional format that when the value is null to format it to #,##0;-#,##0;0

For these two columns the values are returning correctly.

After this I defined a new calculated measure that as follows:

"Payables Invoices - Transactions Real Time"."- Invoice Amounts"."Invoice Amount"-"Payables Invoices - Transactions Real Time"."- Invoice Amounts"."Paid Amount"

This I called Amount Due.