Earth Day

Objective:
The students will explore fractions.

Materials

• Circle Worksheet
• Crayons - blue and brown
• Balloons - blue and black or green.  Have them blown up so that 3/4's of them are blue and 1/4 are black or green.  (Try to have about 1 balloon per student.)
• Globe

Procedure

1. While holding up the globe, discuss how the earth is covered by more water than land.  In fact, almost 3/4 (71%) of the earth's surface is covered by water.
2. Give each child one of the blown up balloons.  Have them cluster the balloons together in a designated area.  Discuss how the blue balloons represent the amount of water on earth's surface and the black/green balloons represent the land.  Observe how much more water than land covers the earth.  This will help create a good visual representation.
3. Pass out the Circle Worksheet.  (For younger students, before running off this worksheet, divide the circle into 1/4's to give them lines to cut on.  Older students may use rulers and divide the circle into 1/4's on their own.)
4. Have the students color 3 of the 1/4's blue and the other 1/4 brown or green.  Discuss how this again represents the amount of water vs. the amount of land covering earth's surface.  They should then cut out their circle into the 4 pieces.
5. Work as a class to explore the fractions.  How many 1/4's make 1/2?  How many make a whole?  The amount of depth will depend on the age of the students.  Older students may be able to follow up by writing some fraction problems involving 1/4's.  Challenge them by combining their circle parts with a partners and writing more complex problems.

Other Lesson Ideas

1. Similar to the above lesson, work with 1/2's by discussing the equator and how it divides the earth in half.
2. Work with place value.  Place value boards and manipulatives would be ideal for this lesson.  All the numbers the students work with in the lesson could be numbers relating to the earth.  For example, 7 (for 7 continents), 365 (for how many days it takes the earth to revolve around the sun), 24 (for how many hours it takes the earth to rotate), etc.
3. Complete story problems relating to time zones. Use the following link for help http://www.timeanddate.com/. 
4. Have a lesson on 3 dimensional shapes, including spheres, cylinders, cones, and cubes.  Refer to the Bubble Day Math Lesson for ideas.