Вычислить, чему равна сумма цифр числа

Sub Irina()
MsgBox Array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 2, 3, 4, 5, 6, 7, _
    8, 9, 10, 11, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 5, 6, 7, 8, _
    9, 10, 11, 12, 13, 14, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 7, 8, 9, 10, 11, 12, 13, 14, 15, _
    16, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 1)(InputBox("n="))
End Sub

Sub Irina212121()
Dim n&, s&
n = Val(InputBox("n="))
Do While n > 0
    s = s + n Mod 10
    n = n \ 10
Loop
MsgBox s
End Sub

Sub t()
  Dim n&, ns$, i%, s%
  n = Val(InputBox("n=")): ns = CStr(n)
  For i = 1 To Len(ns)
    s = s + Mid(ns, i, 1)
  Next
  MsgBox s
End Sub

Sub aa()
Dim s$, sum%, a As Byte, b() As Byte
s = CStr(InputBox("Введите число: "))
b = s
For a = 0 To UBound(b) Step 2
    sum = sum + b(a) - 48
Next
MsgBox "Сумма цифр числа " + s + " = " & sum
End Sub

Sub vv()
Dim s$
With CreateObject("scriptcontrol")
    .Language = "VBScript"
    s = InputBox("Введите число")
    MsgBox .Eval(Format(s, Replace(Space(Len(s)), " ", "@+") & 0)), , "Сумма цифр"
End With
End Sub

Sub SelectedValDigitsSumma()   'F7 in my Normal.dot
    With Selection
        .text = Format(.text, "@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ ")
        InputBox .text, "Сумма цифр выделенного числа", .Calculate
    End With
    ActiveDocument.Undo 1 'убрал разбивку на цифры
End Sub

Function sumDig(n as long)
  if n < 0 then 
     sumDig(Abs(long))
  elseIf n < 10 then
     sumDig=n
  else
     sumDig=(n mod 10) + sumDig(n \ 10)
  end if
End function

Function sumDig(n As Long)
  If n < 0 Then
    sumDig = sumDig(-n)
  ElseIf n < 10 Then
     sumDig = n
  Else
     sumDig = (n Mod 10) + sumDig(n \ 10)
  End If
End Function

Function sumDig(n As Long)
  If Abs(n) < 10 Then
     sumDig = Abs(n)
  Else
     sumDig = Abs(n Mod 10) + sumDig(n \ 10)
  End If
End Function