When you select a list from the Listpicker, only one number appears at the front.
For example, if you select 100, it will be 1, if you select abc1, it will be 1, and so on.
I want to know how to solve it.plz~
Are you returning selection.index instead of selection ?
It would really help if you provided a screenshot of your relevant blocks, so we can see what you are trying to do, and where the problem may be.
To get an image of your blocks, right click in the Blocks Editor and select "Download Blocks as Image". You might want to use an image editor to crop etc. if required. Then post it here in the community.
Taifun
Trying to push the limits! Snippets, Tutorials and Extensions from Pura Vida Apps by 
Taifun.
We are not able to translate your blocks from images.
Can you temporarily change the AppInventor language to English and post those blocks here.