Calculation of DFF value based on other dff value

Summary:

Hi,

Business want to enter initial value of PO on the PO header dff. An in another two dff's business wants to have two values as Saving Amount= (Intial amount- PO ordered value) and Saving Percentage = (Intial amount- PO ordered value)/100 based on above formula.

How can we achieve this in oracle ?

Content (required):

Hi,

Business want to enter initial value of PO on the PO header dff. An in another two dff's business wants to have two values as Saving Amount= (Intial amount- PO ordered value) and Saving Percentage = (Intial amount- PO ordered value)/100 based on above formula.