Sears CI 801.58000 Desktop Electronic Calculator

This lightweight desktop electronic calculator has a turquoise and gray plastic case, an array of nine digit keys, and a zero bar and decimal point key below the digit keys. Keys for the arithmetic operations, a percent key, an equals key, and a cancel key are right of these. The liquid crystal display is behind the keys, and the power switch is on the side. The calculator has prongs for a cord but no cord. It has a clear plastic cover.
A stamp on the bottom of the inside of the case reads: 111772.
A mark above and behind the display reads: Sears C1. A sticker on the bottom reads in part: MODEL (/) NUMBER 801.58000 (/) CALCULATOR (/) # 142329. It also reads in part: ASSEMBLED IN MEXICO.
Sears reportedly first sold an electronic calculator in 1972. An advertisement for the C1 appeared in the Boston Globe in January of 1973, listing the machine as on sale for $89.88, $10.07 off the usual price of $99.95. The ad indicates that the calculator had an eight-digit capacity.
“Sears Catalog Geared to Special Customers,” Chicago Daily Defender, January 15, 1972, p. 16.
[display ad], Boston Globe, January 21, 1973, p. A6.
Currently not on view
Object Name
electronic calculator
date made
ca 1972
Sears, Roebuck and Co.
Physical Description
plastic (case, keys material)
glass (display material)
metal (wiring material)
overall: 14.732 cm x 24.892 cm x 7.112 cm; 5 13/16 in x 9 13/16 in x 2 13/16 in
place made
ID Number
catalog number
accession number
Computers & Business Machines
Desktop Electronic Calculators
See more items in
Medicine and Science: Computers
Desktop Electronic Calculators
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of John B. Priser
Additional Media

Visitor Comments

2/12/2015 1:09:23 PM
Emil Butler
I purchased one of these calculators when they first came out (1972). I believe I paid $77.00 for it on sale at Sears. I was an IBM technician at the time, and I used it a lot before buying a handheld unit by HP when they became available. I still have the C1 and it continues to function flawlessly. I later became an engineer / scientist at IBM, and I still have all of my scientific calculators from the time, and all continue to work. I retired from IBM in 1993..
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