Friden Model FT 10 Calculating Machine

This full-keyboard electric stepped drum calculating machine is non-printing. It has a metal frame painted gray and ten columns of color-coded light-green and blue-green plastic number keys, with a blank green clearance key at the bottom of each column. Metal rods between the columns of keys turn to serve as decimal markers.
On the right are two columns of function bars. To the right of these is another column of blue-green keys, with another green clearance key at the bottom. Pushing these keys allows direct multiplication by a single digit. Friden had introduced this feature in its Model F calculating machine. The model FT, of which this is an example, featured division tabulation as well. The company also sold calculating machines in which multiplication by several-digit numbers could occur automatically (see descriptions of the model S 10).
The movable carriage behind the number keys has an 11-digit multiplier register and a 20-digit result register, both with sliding decimal markers. Plastic buttons above the result register rotate to set up dividends. Ten numbered buttons are under the revolution register. Zeroing knobs for the registers are on the right of the carriage. The machine has four rubber feet.
The serial number, marked on the bottom of the machine is: FT10-79740. The side and back are marked: FRIDEN. A sticker on the bottom reads: MODEL FT. It also reads: FRIDEN CALCULATING MACHINE CO., INC. (/) MADE IN SAN LEANDRO, CALIFORNIA, U.S.A.. It has the patent numbers: 2,273,857, 2,229,901, and D-103,425.
The black plastic cover is marked: IBM.
Date from Ernie Jorgenson.
C. M. F. Friden, "Calculating Machine," U.S. Patent 2,273,857, February 24, 1942.
A. I. Richards, "Calculating Machine," U.S. Patent 2,229,901, January 28, 1941.
C. M. F. Friden, "Design for a Calculating Machine with Shiftable Carriage," U.S. Design Patent D103425, March 2, 1937.
E. Jorgenson, Friden Age List, Office Machine Americana, p. 2.
Currently not on view
Object Name
calculating machine
date made
Friden Calculating Machine Company, Inc.
Physical Description
metal (overall material)
plastic (overall material)
rubber (overall material)
overall: 21 cm x 46 cm x 34 cm; 8 9/32 in x 18 1/8 in x 13 3/8 in
place made
United States: California, San Leandro
ID Number
catalog number
accession number
maker number
Science & Mathematics
Calculating Machines
See more items in
Medicine and Science: Mathematics
Calculating Machines
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of The Singer Company, Friden Division
Additional Media

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