Pie chart show incorrect item are majority of slice

[Qlik1_User1]

HI All,

In pie chart when using measure expression as number formatting, pie chart is showing incorrect pie slice share
below is the expression used 

=pick(match(-1,SUM(Sales)>=1000000000,SUM(Sales)>=1000000,SUM(Sales)>=1000),
num(SUM(Sales)/1000000000 ,'#,##0.0 B'),
num(SUM(Sales)/1000000 ,'#,##0.0 M'),
num(SUM(Sales)/1000,'#,##0.0 K'))

As here we can see dimension with 400.5k have more slice area while dimension with value 58.4M has less slice area.
Please help here.

[Kimberly748]

Comparing pie charts of different sizes could be misleading as people cannot accurately read the comparative area of circles. The usage of thin slices, which are hard to discern, may be difficult to interpret. The usage of percentages as labels on a pie chart can be misleading when the sample size is small. Emory Healthcare Patient Portal

[Qlik1_User1 · Accepted solution]

with Dual expression is working
=DUAL(pick(match(-1,SUM(Sales)>=1000000000,SUM(Sales)>=1000000,SUM(Sales)>=1000),
num(SUM(Sales)/1000000000 ,'#,##0.0 B'),
num(SUM(Sales)/1000000 ,'#,##0.0 M'),
num(SUM(Sales)/1000,'#,##0.0 K')),UM(Sales))