This is a rare calculator pencil made by Ruxton Multi-Vider of New York in 1929.  It is made of Bakelite with 14-karat Gold filled trim.  This is the Executive model.  The box advertises instrument multiplies and divides.  By sliding side of pencil to desired calculation, answer is given.  Removing top reveals a worn eraser.  Pencil has a red colored lead.  Included is a photo copy of 11 page directions.  This 81+ year old instrument is in good operational condition.  Tip of eraser cover has a small dent.  Top of the box is missing one side and other taped, but has preserved this calculating treasure in good condition.  Collectors of engineering calculating and computing history memorabilia will find this a highlight.