Attribute VB_Name = "Module1"

Private Sub Laskennat(ByVal Kerroin As Double)
  MsgBox Kerroin
End Sub

Public Sub Avaukset()
1  Dim Kr As Double
2  KerroinValinta.Show
3  Kr = ThisWorkbook.Sheets(1).Range("A1").Value
4  Laskennat Kerroin:=Kr
End Sub