APF Mark 25 Memory Handheld Electronic Calculator

This handheld electronic calculator has an array of ten white digit keys and five black keys for the four arithmetic operations and percentage. Red keys are for a decimal point, EX, clear entry/clear, equals, four memory functions, and D (display). A vacuum fluorescent display for eight digits and a decimal point is behind the keys. A battery compartment is at the top.
A mark above the keyboard reads: aPF MARK 25/MEMORY. A silver-colored paper tag on the back gives operating instructions. Toward the bottom of this tag it reads: APF ELECTRONICS INC (/) MODEL MARK 25 (/) SERIAL # K55342 (/) THIS CALCULATOR TO BE USED ONLY WITH APF LISTED A.C. ADAPTER MODEL 710 OR MODEL 716 (/) MADE IN U.S.A. A mark inside the lid of the battery case reads: JAPAN (/) K-140032.
A February 1975 advertisement in the Los Angeles Times indicates that the APF Mark 25 sold for $24.95 with an additional $4.95 for the power adapter. A November 1975 advertisement in the New York Times indicates that the APF Mark 25 pocket calculator (with eight-digit display) regularly sold for $19.95 and could be purchased for $17.95, with a few dollars more for the power adapter. A February 1976 advertisement in the Los Angeles Times indicates that the APF Mark 25 sold on clearance for $19.99.
Los Angeles Times, February 28, 1975, P. A26.
New York Times, November 2, 1975, p. 46.
Los Angeles Times, February 27, 1976, p. B9.
Currently not on view
Object Name
electronic calculator
date made
ca 1975
APF Electronics
Physical Description
plastic (overall material)
paper (tag material)
rubber (feet material)
overall: 1 in x 2 7/8 in x 5 3/4 in; 2.54 cm x 7.3025 cm x 14.605 cm
ID Number
catalog number
accession number
Handheld Electronic Calculators
Computers & Business Machines
See more items in
Medicine and Science: Computers
Handheld Electronic Calculators
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of John B. Priser
Additional Media

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