using powershell to open multiple txt files in directory

i am trying to open 20+ .txt files in a directory.
i navigate the shell into the directory and tried to issue the following commands but they fail:

1. ./*.txt
   //however t6.txt is a file in the directory and the command ./t6.txt works to open the single file

2. notepad.exe Get-ChildItem .*.txt since notepad.exe .t6.txt works i tried this

3. notepad.exe | Get-ChildItem *.txt opens an untitled blank notepad instance?!

i have found some really great answers that provide solutions including this one!

i think i have a fundamental misunderstanding of how the shell works underneath the hood.
i am a lot surprised that i couldn’t find this question elsewhere.
i think that explanations to how these statement are dumb/stupid/bad may provide the context necessary for me to interpret the documentation properly and un-!#@$ my thinking. thanks for the help in advance