Fun Ideas for Getting A-Round in Math CIRCLES by Catherine Sheldrick Ross

Mathematical Strand:

Geometry

Topic:

Students will see circles in real life and have fun with them

Grade level:

6-8

Lesson created by:

Marilyn Kilgore, Susan B. Anthony Middle School, Manhattan, KS

Lesson Description:

Materials

• The book Fun Ideas for Getting A-Round in Math CIRCLES by Catherine Sheldrick Ross, compasses, string (1 yard), 12"by1" paper strips, rulers, one bubble mixture and one large paper circle.
  

1. Launching the lesson (engage)

1. Read page 5 in book
   
2. Show large paper circle
   
3. Ask students what they can tell about this circle (circumference, area, pi, radius, diameter, 360 degrees.)
   
4. Read page11 (right side of page only)
   

2. Developing the lesson

1. Hand out string (36 in.) that has been knotted to form a loop. Ask each student to use his or her string to decide which shape triangle, square or circle would form the largest area. Give the students time to use their string to form each shape and find the area of each shape.
   
2. When the class agrees upon the shape that would give the largest area, read page18.
   
3. Ask the students to give some opposites (black/white, old/new, dry/wet, male/female etc)
   
4. Hand out a compass, ruler and white construction paper to each student.
   
5. Follow directions on page 24-25 and direct students to make Yin and Yang. Must have 25-30 min. to complete this.
   
6. Start blowing bubbles around the room. Ask students if these are circles. Ask what they are called. What are some other spheres in real life? Explain every place on the outside of the surface is exactly the same distance from the center. This means you can cut a slice through anywhere and get a circle. Cut a slice in an orange to demonstrate this.
   

3. Closure/Discussion

1. Ask students to decide if a sphere, disk or ring would win a race down a slope. See page 76