Ratio and Proportion

Valesta Cobbs                  John Fiske Elementary School
                               6145 S. Ingleside Ave.
                               Chicago IL 60637
                               (312)535-0990

Objectives:

     The students will use the phenomenological approach to complete the 
activities, calculate ratios and proportions and compare and contrast group data 
with class data.


Materials Needed:

     Four 16 oz. bags of candy 
     Rice (2 different amounts of the same brand)
     Cereal (2 different amounts of the same brand)
     Tuna (2 different amounts of the same brand)
     Canned Corn (2 different amounts of the same brand)
     Gum (2 different amounts of the same brand)
     Canned beans (2 different amounts of the same brand)
     6 sets of 10 ratio cards with easily identifiable items to be
       compared (For example: girls to boys) 
     Timer

Strategy: 

     Review the definition of a ratio.  Ask the students to write the number of 
vowel letters and consonant letters in their name as a ratio of vowels to 
consonants on a sheet of paper.  Ask three or four students to come to the board 
and write their name and the ratio of vowels to consonants.  

     Divide the class into groups of five.  Give each group ten ratio cards. 
Explain the directions and set the timer for five minutes.  After the elapsed 
time, tell the students to stop.  Ask one student from each group to write the 
group data on the board.  Have the students line up on opposite sides of the 
room according to the ratio.  For example, if the students identify the ratio of 
boys to girls, then the girls will line up in the front of the room and the boys 
will line up in the back of the room.  Have one student count the number of boys 
and girls and check the answer on the board to make sure that it corresponds to 
the numbers counted. 

     Review the definition of proportion.  Give each group a bag containing at 
least 10 pieces of candy.  Clearly mark or label the price of the bag of candy.  
Ask the students to find the cost of one piece of candy.  Have a student from 
each group record the group data on the board.  Ask a member of each group to 
orally state the unit price of one piece of candy in the bag of the group.  Ask 
the class to determine if the data written on the board is correct. 

     Give each group two different amounts of the same product.  Ask the 
students to determine the cost of one ounce of each product and the best buy.  
Select one member of each group to write the group data on the board.  Ask a 
member of each group to explain the data written on the board for that group.  
Have the class check the data written on the board. 

Performance Assessment:

     Give each group two different amounts of another product.  Ask the group to 
determine the cost of one ounce of the product and the best buy.