Powershell 3 of 3

You can save a PowerShell function to a script file with the `.ps1` extension. Here's how you can do it:

1. Open a text editor such as Notepad and paste the function code into it.
2. Save the file with a `.ps1` extension, for example `Add-Numbers.ps1`.
3. To use the function, you need to **dot-source** the script file in your PowerShell session. This means that you need to run the script file in the current scope so that the function is added to your session.

To dot-source a script file, use the `.` operator followed by the path to the script file like this: `. C:\Path\To\Add-Numbers.ps1`. After dot-sourcing the script file, you can use the `Add-Numbers` function in your session.

Make sure that your execution policy allows running scripts. You can check your execution policy by running `Get-ExecutionPolicy` and set it by running `Set-ExecutionPolicy`.