This handheld electronic calculator has a gray and black plastic case with an array of twenty-three square plastic keys. These include ten digit keys, a decimal point key, a total key, four arithmetic function keys, four memory keys, a percentage key, a clear key, and a clear entry key. Right of the top three keys is an on/off switch. Behind this is an eight-digit red LED display. A mark behind this reads: UNITREX 91PM.
A power jack is on the right side near the bottom.
The back of the calculator has a compartment for a nine-volt battery at the top. A sticker below this reads: ELECTRONIC CALCULATOR (/) DC 9 VOLT (/) USE 1 PIECE 9 V BATTERY (/) MADE IN HONG KONG.
Reference:
[Advertisement], Chicago Tribune, January 30, 1977, p. M1. Calculator on sale for $8.88, regularly $9.95. “Save $2”!
Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.
If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.