Alternative to Get-Random method in Powershell?

There is a text file which contains many fields. My purpose is to get a a new random number and save the file every time my script runs.

$Number = Get-Random -Maximun 999

However, i noticed a weird things, that when i use the Get-Random method in my script, it adds extra dummy numbers into other fields(records) in my text file.

Now, is there any other alternative to change a number everytime. I doubt that i can generate a new number everytime and save it n a field of a text file without using this method?