Sub sumarango()
Dim NumRange As Range
Dim SumAddr As String
For Each NumRange In Columns("A").SpecialCells(xlConstants, xlNumbers).Areas
SumAddr = NumRange.Address(False, False)
NumRange.Offset(NumRange.Count, 0).Resize(1, 1).Formula = "=SUM(" & SumAddr & ")"
Next NumRange
End Sub