I was in New York City last week and stopped by the new Museum of Math (MoMath at 11 East 26th Street in Manhattan -- not too far from the Empire State Building). A worth while visit, and many excellent exhibits. One exhibit is called "String Product," pictured above from the New York Times Alice in Math Wonderland article announcing the museum's grand opening back in December 2012. String Product is an analog computer that calculates products, such as a times b, where a is on one circle of the sculpture, and b is on another circle with a string connecting a to b. At the center of the structure, from bottom to top, numbers are listed in order, and the ab product can be found by noting where the string crosses the center. The strings are chords of the structure, known as a paraboloid. A subsequent Times page provides additional information on the museum, and includes a description of how the string product functions.