Learn How to Calculate Discounts to SAVE, SAVE, SAVE Using a Graphic Organizer

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Objective

SWBAT use a graphic organizer to organize their thinking in order to find discounts.

Big Idea

Let’s apply our prior understanding of number sense, in order to calculate discounts. With the economy as it is, we need to find any way possible to save, save, save!

Pre-Lesson Guided Notes

Pre-Lesson Teacher Guided Notes: In order for students to successfully find discounts, students will need a strong number sense background.  Students will convert percentages to decimals, estimate to the nearest hundredth place, multiply decimals, subtract decimals, and identify values of decimals. Students should use their knowledge gained from 6.NS.B.3 to help calculate the discounts and sale prices. In future lessons, we will learn to model the steps using bar diagrams and tables to calculate discounts.  

Bell Ringer

20 minutes

:  Hand each student the BASKETBALL SHOE SALE BELL RINGER as they enter the room.  Have students work on the problem individually for 10 minutes.  Students will use mathematical practice 1, 2, 4 and 6.

My students have assigned seats for their Individual Think Time seats.  Students will grapple with the problem for 10 minutes on their own.  During this time students may use a variety of strategies to calculate the discount.  Students should explain their thinking, record their work, and articulate the strategy they chose in order to solve the problem.   Wait to give your students the graphic organizer until the student activity.  

After students have had the opportunity to organize their thoughts, think quantitatively, and/or abstractly, try different methods, reorganize their thoughts, and attempt to solve the problem with accuracy, allow the students to pair up with another student or group of students to compare their thinking and results.   Students will be in P.U.T seats.  This is pair up time.  Students will use MP 3 during this time.  Students should defend their thinking with their peers, critique the work of others, and correct mistakes as a result of the mathematical discussions.  Allow students 10 minutes during P.U.T.

During this time while you walk the room checking for understanding you are looking for students who are able to solve for the discounts. Students who have little to no understanding will attempt to solve the problem by subtracting the percent from the original cost.  For example:

If the problem states: The coat cost $40.00, there is a 50% discount.  How much will the coat cost?  Students tend to understand discount means take off, therefor they will subtract.  If you notice students doing this, ask them does your answer make sense?  What does 50% mean? 

The meat of the discussion will be for students to understand what the percent means, what is the relationship of the percent to the original cost?  How will that information help you solve the problem?  Students should also understand that finding the discount is different than finding the new cost.  The discount is the amount off, the new cost is the price after the discount has been taken off.  

Student Activity

10 minutes

Student Activity:  After students have had the opportunity to grapple through the problem, give them the graphic organizer.  Allow students to use the work accomplished during the bell ringer and adjust thinking using the graphic organizer.  Allow students 10 minutes to use the graphic organizer.  During this time assess if the graphic organizer reorganizes student thinking.  The graphic organizer will help students who have little understanding gain starting points, isolate the stages of the process, and help students build understanding of the process in order to build other strategies to calculate discounts. 

Closing

10 minutes

Closing: Due to the time of this lesson, we will bypass the whole group discussion. Open your next day lesson with the whole group discussion.  In this closing, use your Smartboard, document camera, white board, or chalk board to go over the graphic organizer.  Have students check their work as you go over each step of the graphic organizer.  If students make mistakes, encourage them to correct their mistakes, and also keep note of the mistakes they made to talk about them during the whole group discussion during the next day lesson opener. 

 

Homework

Have students complete the homework.  Item 1 students will use the GRAPHIC ORGANIZER. Item 2 students will attempt to model to find the discount.