Dear Family,
Have you ever watched the countdown for a space shuttle launch? The time 
remaining to the launch gets smaller and smaller as the launch approaches, 
ending in the countdown "3....2....1....Blastoff!" For those working on the mission, 
time is divided into time before and after the launch. Blastoff is the zero. 
Time before the launch is negative, and time after the launch is positive.
We use a similar method with temperature—both the Fahrenheit and Celsius 
scales set a zero that is within the normal range of temperatures for a cold 
climate. Warmer temperatures are positive, and temperatures colder than 
zero are negative. A similar method is used to describe elevation, with sea level 
as the zero and positive and negative elevations on either side. Geographically 
the equator is set as zero latitude, and other latitudes reference north and 
south of that zero. For longitude the choice of a natural zero was less 
apparent, and so the zero was set through the Royal Astronomical Observatory 
in Greenwich, England. Other longitudes are measured east and west of this 
zero. Richmond, Virginia, for example, is located at 
>
0146+
.$6,67'(
$0'
>

west longitude. Its sister city Windhoek, in Namibia, is found at         >
south 
latitude and >
east longitude.
You can explore the idea of plotting with integers using a globe. First find the 
point that is >
latitude and >
longitude. How would you describe the location 
of a favorite spot, such as your home or a favorite vacation destination? What 
is on the opposite side of the globe from that place?
Happy hunting!

 

Mrs. Lounsbury