additionner plage de cellule en vba

Sub couleur_bleue()
Application.DisplayAlerts = False 'pas de boite de dialogue
Application.ScreenUpdating = False 'macro silencieuse
X = Selection.Rows.Row 'selectionner lignes
Y = Selection.Rows.Row + Selection.Rows.Count - 1
Set plage1 = Range("A" & X & ":" & "t" & Y)
Set Plage2 = Range("s" & X & ":" & "s" & Y)
Set Plage3 = Range("t" & X & ":" & "t" & Y)
Set Plage4 = Range("s" & X & ":" & "t" & Y)
Set Plage5 = Range("q" & X & ":" & "q" & Y)
Set plage6 = Range("ae" & X & ":" & "ae" & Y)

plage1.Select
   With plage1 'surligner en bleu et double trait
    Selection.Borders(xlDiagonalDown).LineStyle = xlNone
    Selection.Borders(xlDiagonalUp).LineStyle = xlNone
    Selection.Borders(xlEdgeLeft).LineStyle = xlNone
    With Selection.Borders(xlEdgeTop)
        .LineStyle = xlDouble
        .ColorIndex = 0
        .TintAndShade = 0
        .Weight = xlThick
    End With
    With Selection.Borders(xlEdgeBottom)
        .LineStyle = xlDouble
        .ColorIndex = 0
        .TintAndShade = 0
        .Weight = xlThick
    End With
    Selection.Borders(xlEdgeRight).LineStyle = xlNone
    Selection.Borders(xlInsideVertical).LineStyle = xlNone
    Selection.Borders(xlInsideHorizontal).LineStyle = xlNone
    With Selection.Interior
        .Pattern = xlSolid
        .PatternColorIndex = xlAutomatic
        .ThemeColor = xlThemeColorLight2
        .TintAndShade = 0.799981688894314
        .PatternTintAndShade = 0
    End With
    End With
plage6.Value = Application.WorksheetFunction.Sum(Range("f" & X & "f" & Y))