With GPS technology built into almost all our handheld devices these days, it’s easy to forget how our device is able to determine just exactly where we are. So for this class, we put away our smartphones and learned latitude and longitude the good ole’ fashioned way — with a map and globe (well, sort of…)
First, we explained to the class that latitude lines run from north to south and longitude lines run from east to west on the globe. We also discussed that values have a unit of degrees (but not the same as temperature degrees) and are written as coordinates, just like how you see graphing coordinates in a Cartesian coordinate system!
Once the discussion ended, each student was given a balloon to inflate which acted as their “globe” for this fun activity. First, they drew the equator around the middle and from there, they labeled the North/South poles (90°). They then drew one more parallel line in both hemispheres to represent 45°. Before drawing longitudinal lines, we gave the students several latitudinal coordinates and had them point it out on their globe (e.g. find 55° N).
Once the class understood that concept, we moved on to drawing our longitudinal lines. We explained the Prime Meridian is somewhat similar to the Equator in that it’s the “middle” (aka 0°) for the longitude lines. However, it differs because it can be placed anywhere on the globe but it must run through the North/South poles. Miss Christy explained to us that the Prime Meridian has changed its location throughout history and currently it’s positioned in Greenwich, London. Once again, students drew their lines on the globe to represent longitude starting at the Prime Meridian (O°) and going up to 180° on both hemispheres, making sure that each line crossed through both poles. We did the same exercise of having students find a given location on their longitude lines.
We asked the class, “Can you figure out an exact location with just one coordinate?” Well of course not, you need BOTH coordinates of latitude AND longitude in order to find the precise location. So with this in their minds and their globes in their hands, we asked them to find a place on their globes using the given coordinates. We did this same activity using laminated paper maps. However, instead of the teachers giving coordinates, we had students provide the coordinates for latitude/longitude for their classmates to locate on the map. On top of that, students also picked a spot on their maps and asked their classmates to give the coordinates of their location.
To finish off the day, we introduced the class to handheld GPS units. We taught them how to properly use the device and then sent them on a treasure hunt. The students got into pairs and each group was responsible for hiding candy and writing down the coordinates of their hiding spot. Then they swapped their secret locations with another team, and it was their job to enter the ‘new’ coordinates into the GPS and go find their special prize!
By the end of class, everybody was able to use the GPS units to discover their treat!
These GPS skills will be super useful later in the year for tagging our scientific data!