The concept of latitude and longitude can be tricky for students, and I have found that using an orange to demonstrate is not only a fantastic visual, but makes for a fun snack!
I’ve put together a little video demonstration, but you can read the steps below. If you are interested doing this demonstration in your own classroom, you can download the full lesson plan, student worksheet pages, and interactive notebook pages for FREE here: Latitude & Longitude Demonstration Lesson
Materials: For this lesson, you will need sharpies and oranges. I like to use two large navel oranges to demonstrate. I use the first orange to draw the lines on latitude, and then I use the second orange to peel and use for lines of longitude. By using two oranges, I can review at the end of the lesson.
I find a more cost effective way to conduct this lesson is to give each of your students a mandarin or clementine orange. If you want to use full size oranges, then break students into pairs or small group. I honestly prefer using the clementine oranges because they are easy to peel and less messy. Plus each student gets their own orange.
I use the lesson plan worksheet pages as I conduct this lesson, so that as students mark the features on their orange, they can then solidify the concept by referring to the globe on their worksheet. I also provide time for students to answer the questions before I move on to the next concept.
The first thing I do, is begin by explaining our learning objectives. In this lesson, students will be able to identify features of the geographic coordinate system on Earth using an orange as a visual. I like to explain up front, that at the end of the lesson, they will be able to eat their orange. However, if they move ahead and eat the orange before the lesson is complete, there will be consequences (per your classroom accountability system).
Sphere: First discuss that the earth is a sphere—or round. This is a known fact for more than 2,000 years. The ancient Greeks measured shadows during summer solstice and were able to calculate the earth’s circumference. Now, the earth is not a perfect sphere. And likewise, the orange is a sphere, but is not perfectly round, so this is a perfect visual. The earth is slightly flat at the North and South poles because of the force caused when the earth rotates. Have students find the stem. This represents the North Pole. Mark with the letters NP using a sharpie. Then find the blossom. This represents the South Pole. Label with SP. Refer to the North & South Poles on a map and globe before moving on. Have students complete worksheet section.
Equator: Next, have students find the halfway point between the North and the South Pole. Draw a line all the way around the orange. This represents the equator. The equator is the imaginary line that is equidistant between the North and South Poles. Label the equator with an E. Refer to the equator on your globe and world map. Have students label their sheet.
Northern & Southern Hemispheres: Now that the line to represent the equator is drawn, discuss hemispheres. The Northern Hemisphere is the area from the equator to the North Pole. About 90% of the world’s population lives in the Northern Hemisphere. Have students label this section with NH. Then locate and label the Southern Hemisphere, which is the area from the equator to the South Pole. I have my students notice that the Northern and Southern Hemisphere each make up half of Earth. Label on worksheet.
45th Parallels: Now, focus on the Northern Hemisphere. Have students draw a line around the orange in the halfway point between the equator and the North Pole. This should divide the Northern Hemisphere in half. This line represents the 45th parallel north. The 45th parallel north crosses Europe, Asia, the Pacific Ocean, North America and the Atlantic Ocean. At this point, Refer to your world map and globe and point out the 45th parallel north. Look to see if the 45th parallel passes through your location. Next, do the same process for the 45th parallel south. Students should locate the Southern Hemisphere, and find the halfway point between the equator and the South Pole and draw a line around the orange. Unlike the 45th parallel north, the 45th parallel south passes through about 97% ocean. Label on worksheet.
Latitude: Now, look at all of the lines on the orange. These lines are called parallels. Parallels are lines of constant latitude. Have your students point to any spot on one of the parallels. This is a circle of latitude. Latitude lines are those that specify the north-south position of a point (geographical location) on Earth’s surface. One way I remember this, is that a circle of “latitude has sat-itude.” You could “sit” on the lines like the rungs on a ladder. Label on worksheet.
I like to then refer to the globe and the map and point out parallels, and then indicate a specific point to demonstrate latitude.
Now, have your students peel the orange. Once your students have peeled the orange, remind them that it can be tempting to eat, but they have a few more things to identify first.
Make sure you use your second orange for the next part of the demo (keep the unpeeled orange with lines as a visual).
Prime Meridian: Have your students identify the North and South Poles on their peeled orange. Now, have them pick any one of the “lines” from the orange. Then have them find that exact same line directly on the other side of the orange. This is called the Prime Meridian. A meridian is a line of longitude, and the Prime Meridian is half of an imaginary circle on Earth’s surface, dividing from North to South Pole. The opposite side is called the anti-meridian. Together these divide Earth into two sections. Refer to your globe and map and point out the Prime Meridian. Label on worksheet.
Eastern & Western Hemispheres: Now have your students gently pull the orange apart in halves. The two sections from the Prime Meridian and the anti-meridian create the Eastern and Western Hemispheres. The Eastern Hemisphere refers to the section of Earth which is east of the Prime Meridian, and west of the anti-meridian. The Western Hemisphere is the half of Earth that lies west of the Prime Meridian. The Western Hemisphere crosses Greenwich London. Refer to the globe and map to point this out. Label on worksheet.
Longitude: Finally, I point out that there are many lines of longitude on Earth, and these are represented by the lines on the orange. Lines from pole to pole are lines of constant longitude and are called meridians. Longitude is a geographic coordinate that specifies the east-west position of a point on Earth’s surface. Label on worksheet.