The input will be taken as a string. The output would also be string, but the octal, hexadecimal and binary representations. We will use a .NET accelerator for this.

1. Open a new PowerShell file and type the following:

$InputString = Read-Host "Enter an integer"

Write-Host "Octal representation: " -NoNewline
Write-Host "$([Convert]::ToString($InputString, 8))"

Write-Host "Hexadecimal representation: " -NoNewline
Write-Host "$([Convert]::ToString($InputString, 16))"

Write-Host "Binary representation: " -NoNewline
Write-Host "$([Convert]::ToString($InputString, 2))"

2. Run the script and enter an integer to get the octal, hexadecimal and binary representations of it.

Do not forget to try negative numbers as well.