Lesson 11Percentage Contexts
Learning Goal
Let’s learn about more situations that involve percentages.
Learning Targets
I understand and can solve problems about commission, interest, markups, and discounts.
Warm Up: Leaving a Tip
Problem 1
Which of these expressions represent a 15% tip on a $20 meal? Which represent the total bill?
Activity 1: A Car Dealership
A car dealership pays a wholesale price of $12,000 to purchase a vehicle.
Problem 1
The car dealership wants to make a 32% profit.
By how much will they mark up the price of the vehicle?
After the markup, what is the retail price of the vehicle?
Problem 2
During a special sales event, the dealership offers a 10% discount off of the retail price. After the discount, how much will a customer pay for this vehicle?
Are you ready for more?
Problem 1
This car dealership pays the salesperson a bonus for selling the car equal to 6.5% of the sale price. How much commission did the salesperson lose when they decided to offer a 10% discount on the price of the car?
Activity 2: Commission at a Gym
Problem 1
For each gym membership sold, the gym keeps $42 and the employee who sold it gets $8. What is the commission the employee earned as a percentage of the total cost of the gym membership?
Problem 2
If an employee sells a family pass for $135, what is the amount of the commission they get to keep?
Activity 3: Card Sort: Percentage Situations
Problem 1
Your teacher will give you a set of cards. Take turns with your partner matching a situation with a descriptor. For each match, explain your reasoning to your partner. If you disagree, work to reach an agreement.
Lesson Summary
There are many everyday situations where a percentage of an amount of money is added to or subtracted from that amount, in order to be paid to some other person or organization:
goes to | how it works | |
---|---|---|
sales tax | the government | added to the price of the item |
gratuity (tip) | the server | added to the cost of the meal |
interest | the lender (or account holder) | added to the balance of the loan, credit card, or bank account |
markup | the seller | added to the price of an item so the seller can make a profit |
markdown (discount) | the customer | subtracted from the price of an item to encourage the customer to buy it |
commission | the salesperson | subtracted from the payment that is collected |
For example,
If a restaurant bill is
and the customer pays , they left dollars as a tip for the server. That is of , so they left an tip. From the customer’s perspective, we can think of this as an increase of the restaurant bill. If a realtor helps a family sell their home for
and earns a commission, then the realtor makes , because , and the family gets because . From the family’s perspective, we can think of this as a decrease on the sale price of the home.