1. Start by engaging students in understanding the meaning of "Up to 70% off"
Show the advertisement to students and have them discuss the following questions:
What does this offer actually mean?
a)
Are all products discounted 70%?
b)
Are most products discounted 70%?
c)
What can you expect for the distribution of the discounts?
2. Next engage students in using mental strategies for calculating percents:
Present the following situation to students:
You are buying a video game for your younger brother. You check the ads for 4 stores in the local mall.
Pose the following problems one at a time asking the students to solve the problem using mental strategies - no pencil and paper allowed.
Store 1 - $30.00 at 10% off
Store 2 - $40.00 at 20% off
Store 3 - $50.00 at 30% off
Store 4 - $60.00 at 50% off
After posing the problem, have students turn to a partner to explain their mental strategy. Then have a few students share their strategies. For example, to find 10% off, students can think of 1/10 of $30 or $3.00. For 30%, they could find 10% and multiply it by 3. For each store record the Store's original price, the discount in dollars and the final price of the video game.
3. Engage students in analyzing the impact of the discount and the original price:
a)
What is the importance of considering both the original price and the discount combined?
b)
What surprised you?
c)
What else do you notice?
