For some of us, it is hard to imagine writing out long division or simply adding a few numbers without the help of a calculator, possibly the calculator right on our phone! For the teachers who told us we needed to learn extensive math skills because we “won’t always have a calculator” with us, it may be frustrating to see that this is now largely untrue. But electronic calculators have only been in circulation for a relatively short amount of time.
Early versions of mechanical calculators, appropriately named “adding machines,” were clunky pieces of office equipment and specially designed for bookkeeping purposes. Their invention is recorded all the way back to 1642, with credit given to two men named Blaise Pascal and Wilhelm Schickard. However, adding machines did not become popular from a commercial standpoint until 1887 when Dorr E. Felt developed a version that he called a comptometer.
In the United States, this later design of the adding machine w as made to read in dollars and cents. In order to add numbers into a new list, the user would first have to “zero” out the adding machine, similar to clearing a calculator as we do today. The rest of the process was slightly more complicated, as keys had to be pressed multiple times in order to do more complex math like multiplication.
Other buttons on the machines include variations of “Total,” “Subtotal” and “Multiply.” Some models of adding machines have “full keyboards,” which includes a total of 54 keys. Smaller models can have as few as ten keys, which were first available to the public in 1903. Today, ten-key adding machines are the standard and most frequently used.
The Gateway Museum is proud to display a comptometer by Felt & Tarrant, as well as a Burroughs adding machine. There is even a Remington Rand adding machine available for purchase at The Past Antique Marketplace! Come visit us at Nature’s Art Village on Route 85 in Montville, Connecticut to explore all of our historic artifacts and collectibles.