Geography courses and textbooks are usually crammed full of ideas and facts. Sometimes they do not include somewhat practical information that can be very useful. In this article, we will explore some simple practical information that allows students to make some fairly accurate predictions based on limited information. Some of this information is sufficiently systematic that it allows fairly accurate predictions, some is less systematized, but far from random. Let's take a look at some simple practical numbering systems that may reveal more than you expected.
Postal codes are used to help ensure that mail is directed to specific locations around the world. Germany was the first country to introduce postal codes in 1941. The United Kingdom introduced a system using both numbers and letters in 1959. The United States Postal Service launched their national postal code service in 1963. At this point, although there are at least 117 countries with postal codes, there are still countries such as Vietnam, Ireland, and Panama which do not use them.
In the United States, the entire country has been carefully divided into postal regions. Each region bears a specific 5-digit code to mark its location. An additional 4 number code also exists for some smaller geographic areas or for specific addresses which receive a large volume of mail. The point that allows a student to predict the likely area for a piece of mail is the fact that the postal code numbers increase as the zones are labeled from east to west. The east coast has lower numbers including zip codes starting with 0-3; the west coast has the higher numbers including zip codes starting with 9. A student could look at a zip code and get a pretty good estimation of how far to the west that postal code area might be.
The major U.S. Interstate highway system, known as the Dwight D. Eisenhower National System of Interstate and Defense Highways, gives us another example of how knowing some isolated facts about interstate routes can help make accurate prediction about other routes. Once again, Germany was the first country to develop major highway routes for faster, more efficient transportation. Dwight Eisenhower saw the benefit of such a system in America for trade and for defense. His interstate system began to be built during his presidency after the Second World War. These interstate highways consist of almost 50,000 miles of roads. All of these routes are numbered with two-digit numbers. Interstates that run from East to West are generally given even numbers. Interstates that run North to South are given odd numbers.
Unlike postal codes, highway numbers do not have a pattern of getting larger as they cross the country. Some interstates pass through major cities, while others are routed around the city center. Such optional routes around a major cosmopolitan area are designated with three numbers each one beginning with the number 4. Interstate 481, for example, provides an alternative route around the city of Syracuse, New York. Also, generally speaking, the east-west Interstate numbers are lower in the South and higher in the North. Interstate #10 is the most southerly route across America. Interstates #90 and #94 are the more northerly passages with Interstates #80, #70, and #40 sandwiched in between. So if a student read that a traveler was on Interstate 70, they could predict that the person was traveling in an east-west direction on an Interstate that ran between Interstate #40 and #80 somewhere in the central area of the nation.
In most states, exits along these interstates have a specific numbering system as well. The exit numbers correspond to the distances from the state border. This information could assist in determining how far you have come and in estimating how long it will take to reach the next town, city or state border along the way.
Telephone Area Codes
Part of the world of communications is the World Telephone Numbering Guide. This guide keeps track of the numbering systems used in almost every county in the world. As with postal codes and highways, there is no one universal system in use. Different countries use a varying number of digits to create a telephone number. Across North America there is relative consistency. All area codes consist of three numbers; all telephone numbers consist of seven digits. Recently it has becoming necessary to dial all ten digits in most places.
Some area codes are geographically defined by boundaries. These area codes affect telephones which are hard wired and are referred to as "land lines." As these area codes become booked and the numbers available for new telephone users are exhausted, new area codes are formed. A single are code may be split in two with half retaining the old area code number and the other half being designated by a new area code. This was recently the case in Toronto, Ontario, Canada, when the old 416 area code became exhausted. The other cities which ring the core of the Toronto were sheared off and given a new 905 area code. The same phenomenon is happening now in the rapidly expanding city of Phoenix, Arizona.
There are other area codes-such as 800, 877, and 888-which are not geographically bounded. They are used for regional or national toll-free numbers.
The most recent non-geographic development is the area codes used for wireless communication such as cell phones and personal assistance devices like the Blackberry. These devices will almost certainly cause the creation of another large number of area codes.
Airplane Routes and Their Numbers
Everyone who has been to an airport is familiar with the large electronic displays that gives the arrival and departure times for every flight taking off during the next several hours. The flights are listed not only by destination, but also by a flight number. There are at least two kinds of flight numbers. Some are three-digits; others are four digits. The three digit flights indicate that this is the flight of a specific carrier, such as American Airlines or Air India. A set of four digits indicates that it is a flight shared by two airlines that have partnered to maximize the number of passengers for each flight and to free up aircraft and crew for other routes.
The flights are also generally numbered to give the passenger an idea of the direction in which it will travel. Typically, flights headed from east to west will have even numbers, while flights headed west to east will have odd numbers. You may fly Air Iceland Flight 800 from New York to London and fly back on British Airways from London to New York on Flight 801.
Lines of Latitude and Longitude
One system is universally consistent and is used by an increasing number of people every day. These are the lines of longitude and latitude. Like all systems they are numbered in a particular way. In this case, the Prime Meridian which is numbered zero degrees, runs through London, England.
Prior to the development of this grid of lines, early adventurers had great difficulty locating themselves in oceans or on broad flat plains where there were few if any reference points. A system called celestial navigation, of "shooting the sun" at precise times with an astrolabe gave them important data to be able to fix their position. Compasses also helped by pointing in a northerly direction from which calculations could be made.
But compasses were unreliable because they were based on the magnetic pull of the poles and could become highly variable if they passed close to other magnetic sources, including those aboard the vessel itself. Now with the advent of a system of 16 stationary "global positioning satellites" in orbit above the earth, a new "GPS" system has been created. A beam of energy from a ship, plane, or car locates three of the satellites in various positions above the earth. These satellites then send back a beam of energy. The point at which the three beams intersect determines your position within approximately twenty feet. The process is known as triangulation and is of immense assistance to aircraft, ships at sea, pleasure boaters, hikers, and a host of others who need to be able to fix a nearly exact position on a map or chart to determine safe passages. Given as a reading in degrees, minutes and seconds, this "GPS" data clearly illustrates your exact position on the chart.
Obviously many other national and international systems use numbers that would allow us to predict other information. These range from the navigation buoys on our major lakes and rivers to the runway systems for parking and sorting out aircraft. Although these facts and numbers rarely turn up in geography texts, they can provide useful information for any student.
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