David Sundstrand (1880-1930) was a Swedish-born American inventor of the 10-key

adding machine An adding machine is a class of mechanical calculator, usually specialized for bookkeeping calculations. In the United States, the earliest adding machines were usually built to read in dollars and cents. Adding machines were ubiquitous off ...

, 10-key

calculator An electronic calculator is typically a portable electronic device used to perform calculations, ranging from basic arithmetic to complex mathematics. The first solid-state electronic calculator was created in the early 1960s. Pocket-sized ...

keyboard, a 10-keypad now used on computer keyboards, and a co-founder of

Sundstrand Corporation Sundstrand Corporation was founded in 1926 as a merger of the Rockford Tool Company and Rockford Milling Machine Company in Rockford, Illinois. It was known as Sundstrand Machine Tool Company until 1959 when shareholders voted to change the name ...

. Sundstrand's 1914 adding machine had the first now common place keyboard for 10-key calculators and

numeric keypad A numeric keypad, number pad, numpad, or ten key, is the palm-sized, usually-17-key section of a standard computer keyboard, usually on the far right. It provides calculator-style efficiency for entering numbers. The idea of a 10-key nu ...

s. This 1914 invention was filed as patent No. 1198487. This invention was seminal to the development of an extensive range of machines that continued for decades into the 1950s. Sundstrand Corporation Company History;In 1914 David Sundstrand, Oscar's brother and an employee at the Rockford Milling Machine Company, developed a ten-key adding machine.
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References

1880 births 1930 deaths 20th-century American inventors Swedish emigrants to the United States {{US-inventor-stub