Rating is available when the video has been rented.
This feature is not available right now. Please try again later.
Published on Jul 2, 2012
A visual explanation of how pinwheel calculators work. Pinwheel calculators were invented in the 1870's and popular for almost 100 years. The specific details described in this video are for the Triumphator Model K, but the mechanisms are very similar in all pinwheel calculators.