Jaap Scherphuis | The Sterling Dial-A-Matic Adding Machine @jaapsch2 | Uploaded September 2019 | Updated October 2024, 2 hours ago.
The Dial-A-Matic is a simple adding machine with four dials. It was made by Sterling Plastics Co. from 1955 until about 1970. The transparent version was marketed by Selective educational equipment inc., hence the name "see".

For more information in these and other calculators in my collection, visit my site:
jaapsch.net/mechcalc

0:00 Introduction
1:44 Addition
2:28 Subtraction
3:04 Clearing
3:33 Mechanism
6:45 Outro