Show / Hide Sheets based off a cell input

I've seen several ways to hide sheets based off a determined value. The way I have been doing it is like the following:

Private Sub Worksheet_Change(ByVal Target As Range)
Dim sWord As Integer
sWord = Sheets("Master").Range("B8").Value

If sWord = "4" Then
    Sheets("CofA1").Visible = True
    Sheets("CofA2").Visible = True
    Sheets("CofA3").Visible = True
    Sheets("CofA4").Visible = True
    Sheets("CofA5").Visible = False
    Sheets("CofA6").Visible = False
    Sheets("CofA7").Visible = False
    Sheets("CofA8").Visible = False
    Sheets("CofA9").Visible = False
    Sheets("CofA10").Visible = False
    Sheets("CofA11").Visible = False
    Sheets("CofA12").Visible = False
    Sheets("CofA13").Visible = False
    Sheets("CofA14").Visible = False
    Sheets("CofA15").Visible = False
    Sheets("CofA16").Visible = False
    Sheets("CofA17").Visible = False
    Sheets("CofA18").Visible = False
    Sheets("CofA19").Visible = False
    Sheets("CofA20").Visible = False
ElseIf sWord = "5" Then
.....
EndIf

This is clearly cumbersome and could be polished up with a loop. I am not skilled enough ... yet ... to put this code together. Can someone give me a hand in doing this? The spark for this thread came from my code being too long when trying to introduce 40 sheets and the code not executing at all.

Thanks in advance

Evan