APF Mark 21 Handheld Electronic Calculator

This white and black battery-operated calculator has number entry keys, arithmetic function keys, and memory function keys. It also has a clear entry/clear key, a percent key, and an EX key, as well as a decimal point key. There is a nine-digit display. The non-printing device has a sealed, rechargeable battery.
A mark behind the keyboard reads: aPF MARK 21 (/) Electronic Memory Calculator. A plaque on the back gives operating instructions. A mark on it reads: MARK 21 (/) Model No. Another mark on it reads: R-009175 (/) Serial Number. Another mark there reads: APF ELECTRONICS (/) NEW YORK, N.Y. 10022 (/) MADE IN JAPAN. A very small mark in the bottom corner of the plaque reads: 215901.
An October 1976 advertisement in the New York Times lists the APF Mark 21 as regularly priced at $24.99 and on sale for $19. An April 1977 ad in the Los Angeles Times lists the APF Mark 21 as selling regularly for $19.99 and available, with the exchange of any calculator, for a sale price of $14.99.
Los Angeles Times, April 13, 1977, p. A10.
New York Times, October 17, 1976, p. 380.
Currently not on view
Object Name
electronic calculator
date made
ca 1976
APF Electronics
Physical Description
metal (overall material)
plastic (overall material)
overall: 1 in x 3 in x 6 1/4 in; 2.54 cm x 7.62 cm x 15.875 cm
place made
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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