Ken + Add Adding Machine
date: label: date made
content: 1950s
name: label: maker
content: Ken + Add Machines Co.
notes: label: Description
content: This four-wheeled stylus-operated adding machine has two copper-colored wheels for cents and two silver-colored wheels for dollars. There are numbers on the cover around each wheel. No complementary digits are indicated. Above the wheels are four windows that indicate the total. At the back is a plastic container for the metal stylus. Inside the lid of the case is a so-called magic slate for jotting down and erasing numbers. The adding machine, stylus, and slate fit in an aluminum case. The instrument is marked: Ken + Add MACHINES CO. DULUTH, MINN. U.S.A. PATENT APPLIED FOR.
label: Description
content: An account of the Ken + Add appeared in <I>Mathematics Teacher</I> in December 1952, where it was recommended not only as a practical adding machine but as a fascinating toy and an aid to arithmetic teaching. It was advertised in <I>Arithmetic Teacher</I> as late as 1956.
label: Description
content: Reference:
label: Description
content: P. A. Kidwell, A. Ackerberg-Hastings, and D. L. Roberts, <I>Tools of American Mathematics Teaching 1800-2000</I> , Baltimore: Johns Hopkins University Press, 2008, pp. 248-249.
label: Location
content: Currently not on view
place: label: place made
content: United States: Minnesota, Duluth
topic: label: Subject
content: Mathematics
setName: label: See more items in
content: Medicine and Science: Mathematics
label: See more items in
content: Adding Machines
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content: Science & Mathematics
creditLine: label: Credit Line
content: Gift of Robert K. Otnes
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 2005.0278.01
label: catalog number
content: 2005.0278.01
label: accession number
content: 2005.0278
objectType: label: Object Name
content: adding machine
physicalDescription: label: Physical Description
content: metal (overall material)
label: Physical Description
content: plastic (overall material)
label: Physical Description
content: paper (overall material)
label: Measurements
content: overall: 1 cm x 13.2 cm x 6.6 cm; 13/32 in x 5 3/16 in x 2 19/32 in