Private Sub Worksheet_Change(ByVal Target As Range)
   Application.EnableEvents = False
   
   If Not Intersect(Target, Range("A1")) Is Nothing Then
      Macro1
   ElseIf Not Intersect(Target, Range("A2")) Is Nothing Then
      Macro2
   ElseIf Not Intersect(Target, Range("A3:b10")) Is Nothing Then
      Macro3
   End If
   Application.EnableEvents = True
End Sub