Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Application.StatusBar = "" 'RAZ
If Target.Areas.Count <> 2 Then Exit Sub
Dim s1#, s2#
s1 = Application.Sum(Target.Areas(1))
s2 = Application.Sum(Target.Areas(2))
Select Case CStr([A1])
Case "+": Application.StatusBar = "Somme : " & s1 + s2
Case "-": Application.StatusBar = "Différence : " & s1 - s2
Case "*": Application.StatusBar = "Produit : " & s1 * s2
Case "/": If s2 = 0 Then Application.StatusBar = "#DIV/0!" Else Application.StatusBar = "Rapport : " & s1 / s2
End Select
End Sub