Option Explicit
Private Sub Document_ContentControlOnExit(ByVal ContentControl As ContentControl, Cancel As Boolean)
Dim i As Long, j As Long, k As Long, l As Long, m As Long
Dim oCC As ContentControl
With ActiveDocument.Tables(1)
  If ContentControl.Range.InRange(.Range) Then
    For i = 2 To .Rows.Count - 3
     m = m + 1
     Select Case ContentControl.Title
        Case "A", "B", "C"
            If Not IsNumeric(ContentControl.Range.Text) Then
                Cancel = True
                Beep
                ContentControl.Range.Select
                Exit Sub
            Else
                ContentControl.Range.Text = FormatValue(ContentControl.Range.Text)
            End If
            Set ContentControl = ActiveDocument.SelectContentControlsByTitle("PlanA+B/B").Item(m)
             With ContentControl
                .LockContents = False
                .Range.Text = FormatValue(Plan(ActiveDocument.SelectContentControlsByTitle("A").Item(m).Range.Text, _
                              ActiveDocument.SelectContentControlsByTitle("B").Item(m).Range.Text, _
                              ActiveDocument.SelectContentControlsByTitle("C").Item(m).Range.Text))
                .LockContents = True
             End With
            Set ContentControl = ActiveDocument.SelectContentControlsByTitle("PlanA+C/C").Item(m)
             With ContentControl
                .LockContents = False
                .Range.Text = FormatValue(Plan1(ActiveDocument.SelectContentControlsByTitle("A").Item(m).Range.Text, _
                              ActiveDocument.SelectContentControlsByTitle("B").Item(m).Range.Text, _
                              ActiveDocument.SelectContentControlsByTitle("C").Item(m).Range.Text))
                .LockContents = True
             End With
     End Select
   Next
End If
End With
End Sub
Function Plan(ByRef A As Double, B As Double, C As Double) As Double
Plan = (A + B) / B
lbl_Exit:
    Exit Function
End Function
Function Plan1(ByRef A As Double, B As Double, C As Double) As Double
Plan1 = (A + C) / C
lbl_Exit:
    Exit Function
End Function
Function FormatValue(ByRef pStr As String) As String
If InStr(pStr, ".") > 0 Then
    FormatValue = Format(pStr, "##,####,####,###,##0.0###########;(##,####,####,###,##0.0###########);0")
Else
    FormatValue = Format(pStr, "##,###,###,###,###;(##,###,###,###,###);0")
End If
lbl_Exit:
    Exit Function
End Function