7H Percent Project – Cathy’s Shopping Day
This is a Percent Project which includes math and writing. All of the math needs to be neat and
organized, and all of the questions need to be answered in complete sentences. Read the
cartoon carefully and follow the directions carefully. Organization and neatness counts.
1. Suppose Cathy buys a sweater that is marked $90.
a. If the sweater is on sale for 30% off, how much will she pay?
b. If she gets an additional 20% early-bird discount on top of the 30% off, how much will
she pay? Can you solve this problem mentally (without using pencil/paper or a calculator)?
Write down your mental calculation in paragraph form, using complete sentences.
c. If she signs up for a store credit card and gets an additional 10% discount off what
she would have paid in (b), how much will she pay? Again, try to solve using mental math first,
then write down your mental calculations.
d. If Cathy finds a 15% coupon online, which is applied after all the discounts above,
how much will she pay for the sweater?
e. If Cathy receives all the discounts (30%, 20%, 10%, 15%, and an additional 20%
Holiday Bonus Bucks discount, how much will she pay for the $90 sweater?
7H Percent Project – Cathy’s Shopping Day
2. Mr. Riessen, a store clerk, always enters the 30% sale discount before the 20% early-bird
discount. Mr. Ricks, another store clerk, always enters the 20% discount first, and then enters
the 30% markdown.
a. What will Cathy pay at each clerk’s register? Explain, in writing, why your answer
makes sense.
b. Since 20% + 30% = 50%, why isn’t the cost of the sweater with both the sale and
early-bird discounts $45?
3. Suppose Cathy paid $32 for a sweater that was 20% off. What was the original price of the
sweater?
4. Challenge: In this cartoon, the final price of Cathy’s sweater after all the discounts was
$2.50. Assume that Cathy got 20% off her Holiday Bonus Bucks. What was the original price of
the sweater?
5. Now you get to make up your own problem, except you are shopping online not at a store.
You need to neatly show all of the math and write up your solutions. Here is what you need to
include, all answers are to be in complete sentences:
a. Write about what you are buying and the site where you are buying it.
b. Tell me the original price, the discount percent, AND the percent off extra coupon you
have (the total of the 2 percentages cannot be over 45%) as well as the sale price.
c. Show all work and explain in writing how you got the sale price.
d. This is an online sale, so you have an 8% shipping fee you need to ADD to the cost.
Show this calculation and the final price you need to pay, and tell me if you would change your
mind on buying the item knowing it costs an additional 8% due to shipping.
Reread your written explanations and double check all of your math so there are no errors in
your project!