Convert from palmo [Spanish] to city block [East U.S.]

Unit Definition (palmo [Spanish])
The palmo is a traditional unit of distance in Spain and Portugal. The traditional Spanish palmo equals 9 pulgadas or 1/4 vara: this is about 20.9 centimeters in Spain and a little more than that in Spanish Latin America. Under the metric system in Spain, the palmo is an informal unit equal to 20 centimeters. These units are based on the width of a person's outstretched hand, from the tip of the thumb to the tip of the little finger, a definition identical to that of the English span.

Unit Definition (city block [East U.S.])
The city block is an informal unit of distance popular in the U.S. A block is the average distance between street intersections in the rectangular street grids common in most American cities. The length of a block varies from about 1/20 mile (80 meters) in New York to about 1/16 mile (100 meters) in many midwestern cities to about 1/10 mile (160 meters) in cities of the South and West. (In New York and some other cities, streets running on one direction are closer together than streets running perpendicular. In these cities, people often speak of "short blocks" or "long blocks.")