Subtracting to values

[shri]

How to subtract two consecutive rows in a single column or/

how to subtract two rows based on the selection of the filter ?

If Filter pane is of : Materials 

Material     Qty     Result should be 

1234            50               50-20= 30

1334            20               20-10=10

1554            10               10-50= -40

1234            50               50

[JordyWegman]

Hi Shri,

Add the following measure:

Sum(QTY)- Below(Sum(QTY))

Jordy

Climber 

[shri]

It doesn't give me the correct answer 🙁