A set of .NET Framework managed libraries for developing graphical user interfaces.
But that's only simple math: Divide by 5,000, round, multiply by 5,000
Module Module1
Sub Main()
Console.WriteLine(Round5000(21000))
Console.WriteLine(Round5000(22800))
Console.ReadKey()
End Sub
Public Function Round5000(ByVal number As Integer) As Integer
Dim result As Double
result = Math.Round(number / 5000.0, 0) * 5000
Return Convert.ToInt64(result)
End Function
End Module