Friden Model SRQ 10 Calculating Machine

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As early as 1952, the Friden Calculating Machine Company produced a calculating machine that would find the square root of a number entered by simply pushing a key. In 1962 the firm introduced this machine, which would find squares of numbers as well as square roots. It was manufactured until 1965.
The full-keyboard electric non-printing stepped drum calculating machine has a metal frame painted tan and ten columns of light tan and brown plastic number keys, with a brown key at the bottom of each column. The keys at the bottom of the columns are numbered, from left to right, 0 9 9 8 8 7 7 6 6 5 5. These keys are used to set the decimal point in a number whose root is to be taken, and to begin the taking of the root. Metal rods between the columns of keys and under the keyboard turn to indicate decimal places in ordinary arithmetic.
On the right are two columns of function bars. On the left is a register for recording multipliers, with nine light tan keys and a zero bar for entering numbers. Around these keys are three levers and four function keys.
Behind the number keys is a movable carriage with an 11-digit revolution register and a 21-digit result register. White plastic buttons above the result register rotate to set up numbers. Ten numbered buttons are under the revolution register, spaced between the digits. The clearing button is marked C. Zeroing knobs for the registers are on the right of the carriage. All three registers have sliding decimal markers. The base of the machine is covered with fiber. It has a black cord.
The sides, back, and front of the machine are marked: FRIDEN. Above this mark is a square-root sign. A superscript 2 is to the right of it. A mark on the bottom reads: MODEL [/] SRQ 10. Another mark there reads: SERIAL S2000. The serial number under the word SERIAL has been effaced.
Division files.
Currently not on view
date made
The Singer Company. Friden Division
place made
United States: California, San Leandro
Physical Description
metal (overall material)
plastic (overall material)
rubber (overall material)
fiber (overall material)
overall: 22.5 cm x 47 cm x 37 cm; 8 27/32 in x 18 1/2 in x 14 9/16 in
ID Number
catalog number
accession number
maker number
Credit Line
Gift of The Singer Company, Friden Division
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Calculating Machines
Data Source
National Museum of American History


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