SUBJECT: Geography

OBJECTIVE: Younger students will learn their directions-north, east, south, and west. Older students will learn about latitude and longitude. All will study a map of the Evans family farm and use directions (latitude / longitude / north / south / east / west / elevation) to describe the field.

MEASUREMENT: Students will be familiar with the terms "latitude" and "longitude," as well as know their directions (north, south, east, and west). They can visualize a farm field and describe its location.

BACKGROUND FOR TEACHERS:

For the most part we sense our surroundings visually. We see rivers, hills, roads, buildings, or other landmarks, and understand our location as a collection of visible features.

We also think of our location in terms of its relationship to other places. For example, we know where we live in relation to a friend's house, the school, the ocean and so on. Distances and directions from other significant places are very important for our understanding of where we are in the world.

We also think of where we are in relationship to the sun, moon and stars.

Many tools and methods have been used over the years to measure locations. From a compass to a sextant to a GPS receiver, we have needed to be able to document and understand our location in order to find our way.

STUDENT ACTIVITIES:

1. Ask students to read the story David Explores New Worlds. See if they can list some of the ways that people over the centuries have been able to "find their way." (In the story it mentions early explorers like Lewis and Clark using the stars and a sextant. It also teaches about Global Positioning System satellites and receivers (see Lessons 1 and 3). But students should also be able to think of many other methods and tools for "finding their way," from use of simple landmarks and directions ("turn right at the big green house") to compasses and maps.

2. Tell students you're going to use an orange to illustrate the world.

If you insert a long pin through the center, the top of the pin will be the North Pole, and the bottom of the pin will be the South Pole. (Or use two pins with different color heads.)

Longitude lines (meridians) are north (up) to south (down). They are the vertical lines that cut the orange in equal halves from the North Pole to the South Pole. The most famous line of longitude is the prime meridian, which passes through Greenwich, England. The prime meridian is 0 degrees longitude. There are 180 degrees of longitude to the east (right) and 180 to the west (left) of the prime meridian.

The equator divides the earth into two equal parts, the Northern and Southern Hemisphere. The equator is at 0 degrees latitude. There are 90 degrees of latitude to the north (above) and 90 degrees to the south (below). Some famous lines of latitude north of the equator are the Tropic of Cancer (23.5 degrees north) and the Arctic Circle (66.5 degrees north). Some famous lines south of the equator are the Tropic of CapriCORN (23.5 degrees south) and the Antarctic Circle (66.5 degrees south).

• Give each student an orange and a marking pen and ask them to draw the prime meridian and equator, as well as the latitude and longitude lines closest to their home. Place a pin close to their home, then ask them to explain their location using terms like "west of the prime meridian, north of the equator."

3. Choose one of the following activities to increase students' understanding of navigational directions:

• Label the walls of the classroom, north, east, south and west, then ask students to describe where objects are in relation to each other, using directional terms. (For example: "My desk is south of yours, but east of John's." "The bookshelf is northwest of the blackboard.")

• Take students outdoors and use landmarks to point out which ways are north, south, east and west. Then play a game that incorporates navigational directions. One possibility is to split into two teams and ask each team to create a scavenger hunt for the other, using navigational directions. (For example: "Walk to the tree that is 15 steps to the east of the fence, then turn south and proceed to the northwest corner of the garage where you'll find a note buried under a rock.")

• Or, blindfold a student, lead them to a spot, and tell them the class will guide them to a particular location by giving directions. This is difficult, but most students will quickly learn which way is east (to their left) or south (when they're walking on grass instead of on pavement), etc.

Older students can use a compass to follow a map or navigational course.

4. Choose one of the following activities to increase students' understanding of latitude and longitude:

• The web site, "How far is it?" gives the latitude and longitude of any location around the world, and also gives the distance between any two points.

• Discuss the latitude and longitude readings in the story David Explores New Worlds, then see if students can find on a globe the approximate location on Earth where David was standing.

• Ask older students to complete a few calculations using these facts: 1degree of change in latitude = 60 minutes = 364,560 feet = 69.05 miles 1 minute = 1 nautical mile = 6076 feet 1 minute of change in longitude = 1 nautical mile times cosign of latitude

5. Distribute the following maps of Evan's field. (Example 1 & 2) One shows the elevation/hills, and the other shows the field in relationship to fields and rivers in the region.

• Ask students to imagine they are walking across the field. Tell them to describe, or write a story, of their journey from one part of the field to another. (What do they see to the east of them? How tall is the hill to the north of them? Which direction from them is the sun? Etc.)

• Break the students into two groups, and ask one group (using the regional map) to write directions from one point on the map to another. If they give the map to the second group, and point out the starting point, can the second group find the correct destination using the directions given? (Use the river, roads, building sites, and field sizes/shapes as landmarks.)
  

• Ask students how a farmer could use these two maps. (For example, the elevation map might help a farmer determine how water will drain across the field. He or she can build terraces to prevent erosion from washing soil off the hills, and put drainage tile in the low ground so the water can drain away (See Unit 2, Lesson 3 & 4). It might also show the farmer where to put different rates of fertilizers (See Unit 2, Lesson 2). It might help explain different corn yields (See Unit 5, Lesson 2). A farmer might use the regional map to give directions someone delivering corn seed (See Unit 4, Lesson 1) or anyone else who needs to find the field.)