Sub Main()
	Do
		Console.WriteLine("A) Berechnung abc durchführen")
		Console.WriteLine("B) Berechnung def durchführen")
		Console.Write("Aufgabe wählen: ")
		Dim cki As ConsoleKeyInfo = Console.ReadKey
 
		Select Case cki.Key
			Case ConsoleKey.A
				BerechnungA()
			Case ConsoleKey.B
				BerechnungB()
			Case Else
				Exit Do
		End Select
	Loop
End Sub

-----
"There's never enough time to do all the nothing you want."
(Calvin and Hobbes)