Percents: (An application to real life problems)

Lucille H. Chambers              Trumbull School
                                 5200 N. Ashland 
                                 Chicago IL 60640
                                 312-534-2430
 
Objective: (Grade 7)

The students will be able to find a percent of a number by multiplying by a 
fraction or a decimal equivalent to that percent. 

Materials Needed:

One overhead projector, transparencies (4), calculators, play money, 
construction paper, poster boards, pencils and a variety of items to sell at the 
General Store. 

Recommended Strategy:

Review with the students how to write a percent as a fraction and as a decimal.  
Use a circle graph with expenditures.  Have the students guess what percent of 
the circle represents each of the expenditures.  Discuss with the students how 
to calculate a bill for a restaurant meal.  They should know about the local tax 
and tipping customs in the area.  Let's call this activity 'Purchasing Power  
Buying Smart'.  Have each student bring a menu or create one.  The group will 
cooperate by choosing one menu they will use for the activity.  Create a 
restaurant atmosphere on one side of the room and a general store on the other 
side of the room.  

Procedure:

Divide the class into groups of five and give each student a menu.  Each member 
of the group will have an opportunity to order whatever they desire from the 
menu.  Assign one student to play the role of waitperson to write down the 
orders for the group.  Have each student calculate the bill for his or her 
fantasy meal (use a calculator for the food and the tax total).  Another student 
may figure out the tip.  The waitperson will then collect all bills in the group 
and make a final tally to present to the cashier.  After the fantasy meal, 
students have a job to do at the General Store.  They will compute the discount 
prices on selected items to be sold on the following day.  

Performance Assessment:

Choose a group of three students.  The first student will write a percent of a 
number.  The second student will solve it by using a proportion.  The third 
student will solve it by using an equation.  Students take turns in all three 
roles.   

Multicultural Connections:

Student should know that the ancient Egyptians invented proportional scale 
drawing.  In Egypt and Babylonia taxation was based on proportion.  A given 
measure of wheat was the required tax for every one hundred cattle.  

Conclusion:

This activity was fun as well as cooperative learning.  Students used hands-on 
methods to calculate sale tax, find discounts and sale prices using percent.  
Students will use this knowledge to solve problems of applying percent in 
everyday situations.