Monroe Model LA5-160 Calculating Machine


This compact full-keyboard electric non-printing and modified stepped drum calculating machine has a steel frame with rounded corners painted mottled dark green. The steel plate under the keyboard is painted light green. The eight columns of white plastic keys have nine keys in each column. Between the columns of keys, and under the green plate, are metal rods visible through windows in the plate. These serve as decimal markers.

To the right of the number keys are the subtraction and addition bars, two red buttons, one of which is marked R, and a red clearance key. Left of the keyboard is a lever with a red plastic top. In back of the keyboard is the carriage, with 16 result dials and eight revolution register dials. A crank with a wooden handle for clearing the carriage is on its right side and another one for shifting the carriage at the front. The machine has four rubber feet. A gray rubber electric cord plugs into the back, and a light gray cover fits over the object.

A mark on the front of the machine and on the cord reads: MONROE. A mark on the back reads: MONROE (/) REGISTERED TRADE MARK (/) HIGH SPEED ADDING CALCULATOR. The serial number, scratched on the underside of the carriage on the left, is 250245. The cover is marked: MONROE li.

This machine was used to keep the financial records of the Friends Meeting of Washington. Date deduced from serial number.

Compare MA.335424 and MA.334385.


Accession file.

National Office Machine Dealer’s Association, Blue Book, May, 1975, as compiled by Office Machine Americana, January, 2002.

Date Made: 1940

Maker: Monroe Calculating Machine Company

Location: Currently not on view

Place Made: United States: New York, New York City

Subject: Mathematics


See more items in: Medicine and Science: Mathematics, Calculating Machines, Science & Mathematics


Exhibition Location:

Credit Line: Gift of Friends Meeting of Washington

Data Source: National Museum of American History

Id Number: MA.335235Catalog Number: 335235Accession Number: 314611

Object Name: calculating machine

Physical Description: wood (overall material)aluminum (overall material)plastic (overall material)steel (overall material)rubber (overall material)Measurements: overall: 16.3 cm x 29 cm x 28 cm; 6 13/32 in x 11 13/32 in x 11 1/32 in


Record Id: nmah_690561

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