Jordan Simmons, age 13, of Reno, Nev., for his question:

HOW LONG IS A MILE?

A mile is a unit of length. In the customary system of measurement used in the United States, the unit of length used to measure distance on land is called the statute mile, or land mile. It is equal to 5,280 feet.

The Romans were the first to use the mile measurement. Then it was about 5,000 feet long and contained 1,000 paces, each 5 feet in length. The term "mile" comes from "milia passuum," the Latin words for "a thousand paces."

Around the year 1500, the 5,000 feet of the Roman mile was changed to the 5,280 feet of today, although many countries still kept their own length for the mile.

Distances on the sea are measured in nautical, geographical or sea miles. The nautical mile is obtained by dividing the circumference of the earth into 360 degrees and then dividing each degree into 60 minutes. One nautical mile equals one minute, or one twenty one thousand, six hundredth (1/21,600) of the circumference of the earth.