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Old Posted Dec 20, 2014, 7:20 PM
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HossC HossC is offline
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Like C. King and CityBoyDoug said, these machines came with a stylus that fitted into the dials. The user then dialled in the numbers much like an old telephone, and the result would appear in the small circular holes near the top. The one below is a more advanced model with a lever at the side to zero/reset the display. From

The highest number is entered first. The addition is done as each number is entered. Google "10's complement arithmetic" to get an idea as to performing subtraction.

This adding machine can be removed from its stand to show the original coupon with the company's address.

The following adverts are from the June 1951 and January 1952 editions of 'Popular Mechanics'.

The current building at 1260 West 2nd Street was apparently built in 1943, and is very plain and uninteresting. It replaced the building below which housed Falck Radio and the Advance Electric Company back in 1931.

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