# Why is 12 eggs called a dozen?

The term “dozen” is derived from the old English word “dozen,” which means a group of twelve. The concept of using twelve as a counting unit has been around for centuries and can be traced back to various ancient civilizations.

One possible reason for the choice of twelve as a counting unit is its divisibility. Twelve has many factors, including 1, 2, 3, 4, 6, and itself. This divisibility made it a convenient number for calculations and measurements in early societies. For example, twelve can be evenly divided into halves, thirds, quarters, and sixths, which made it easier for merchants and traders to divide goods and quantities.

In addition to its mathematical convenience, twelve also had cultural and religious significance in many ancient civilizations. In ancient Mesopotamia, the Sumerians used a sexagesimal system, which was based on the number sixty. This system had twelve as one of its key components, as sixty is divisible by twelve. The Babylonians, who inherited the sexagesimal system, also utilized twelve as a fundamental counting unit.

The influence of the Babylonians and their sexagesimal system extended to other ancient cultures, including the Egyptians and the Greeks. The Greeks, for instance, used twelve as the basis for their measurement system, with units such as the foot and inch being derived from this counting unit.

The Romans, on the other hand, used a different system of measurement, which was based on the number ten. However, they also recognized the practicality of twelve and incorporated it into certain aspects of their system. For instance, the Roman pound was divided into twelve unciae, which were similar to ounces.

Fast forward to medieval England, and we see the adoption of a measurement system that combined the Roman and Anglo-Saxon systems. This system, known as English units, retained the use of twelve as a counting unit for various goods, including eggs.

The choice to sell eggs by the dozen in medieval England can be attributed to the practicality and convenience of the number twelve. Since eggs were small and relatively inexpensive, it made sense for merchants to sell them in larger quantities. Selling eggs by the dozen allowed for easier calculations and transactions, as well as a standard unit of measurement for eggs.

Furthermore, the monetary system in medieval England played a role in the use of dozens. A penny was the smallest denomination, and twelve pennies made a shilling. Selling eggs by the dozen, with one egg priced at a penny, provided a simple exchange rate of one shilling for a dozen eggs.

Over time, the use of dozens extended beyond just eggs and became a common way to measure and sell various goods. Today, the term “dozen” is still widely used and recognized as a unit of twelve, thanks to its historical significance and practicality.

The use of twelve as a counting unit and the practice of selling eggs by the dozen can be attributed to a combination of mathematical convenience, cultural influences, and historical developments. The divisibility of twelve, its significance in ancient civilizations, and the practicality it offered in trade and commerce all contributed to the establishment of the dozen as a standard unit of measurement.