David Sundstrand

David Sundstrand (1880-1930) was a Swedish-born American inventor of the 10-key adding machine, 10-key calculator keyboard, a 10-keypad now used on computer keyboards, and a co-founder of Sundstrand Corporation.

Sundstrand's 1914 adding machine had the first now common place keyboard for 10-key calculators and numeric keypads. This 1914 invention was filed as patent No. 1198487.[1] This invention was seminal to the development of an extensive range of machines that continued for decades into the 1950s. [2] [3] [4] [5] [6] [7] [8]

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