Sub Delete_Non_Number_Rows()

   ' Dimension variables.
   I = 1
   Set xRng = Selection

   ' Loop once for every row in the selection.
   For xCounter = 1 To xRng.Rows.Count

       ' If it's no numeric, then...
       If Not IsNumeric(xRng.Cells(I)) Then

           ' ...delete an entire row of cells.
           xRng.Cells(I).EntireRow.Delete

       ' Otherwise...
       Else

           ' ...increment I by one so we can cycle through range.
           I = I + 1

       End If

   Next xCounter

End Sub