How do you find the percent of a quantity? For example: According to a survey 10% of people report that mint is their favorite flavor of ice cream. If you sell 300 ice cream cones, how many mint cones can you expect to sell?

In this lesson you will learn how to solve multistep percent problems by using proportions and equations.

Let’s Review

30% of $500 Split $500 into 10 parts 1 part = $50 3 parts = $150

A Common Mistake Percent to Decimal… Divide by 100… move decimal TWO places to the RIGHT

Decimal to Percent… Multiply by 100… move decimal TWO places to the LEFT

Core Lesson A school club sold 300 ice cream cones at graduation.

How many cones of each flavor were sold? Option 1: Using Proportions Van.Mint C.C. Straw.

Proportions Have Equal Between Ratios Van. 50 x 3 = 150 Mint 10 x 3 = 30 C.C. 15 x 3 = 45 Straw. 25 x 3 = 75

Proportions Have Equal Within Ratios Van. 2v=300 v=150 Mint 10m=300 m=30 C.C. 6.67c=300 c=45 Straw. 4s=300 S=75

Proportions Have Equal Cross Products Van. 100v=1,500 v=150 Mint 100m=3,00 m=30 C.C. 100c=4,500 c=45 Straw. 100s=7,500 S=75

Option 2: Using equations Percent as Decimal x Amount Van. 50% = x300= 150 Mint 10% = x300= 30 C.C. 15% = x300= 45 Straw. 25% = x300= 75

In this lesson you have learned how to solve multistep percent problems by using a proportions and equations.

Guided Practice A school club sold 500 cups of soda at graduation. 50% of sales was cola, 20% was ginger ale, 25% was orange, and 5% was grape. How many cups of each flavor of soda were sold?

Extension Activities In the first week of a sale all prices are reduced by 25%. In the second week, the prices are reduced by 25% of the previous week’s prices. In the third week, the prices are again reduced by 25% of the previous week’s prices. In the fourth week, the prices are again reduced by 25% of the previous week’s prices. (Questions on next slide)

Joe says that all items will be free during the fourth week of the sale. Is he correct? How much will a $32 coat cost during each week of the sale. What percentage of the original price are you saving each week of the sale?

Pretend that you want to sell ice cream cones at a school function of your choice. How many people typically attend the function? How much do ice cream cartons and packages of cones cost? How many servings are in a carton? How many cones are in a package? How much does it cost to make one cone? How much do you plan on selling each cone for? (Part 2 on next slide)

Survey a random sample of students to see what percentage of students prefer vanilla, chocolate chip, strawberry, and mint ice cream. Assuming your sample is representative of the attendees of the school function, how much of each flavour will you need to buy? What are expected total costs, earnings, and profit?

Quick Quiz Joe earns 20% commission on his total car sales. This month Joe’s car sales totaled $50,000. How much did he earn in commission? Joe’s credit card company charges him a late fee of 30% of his bill amount if he does not pay his bill on time. If Joe’s bill is $1,000 and he do not pay it on time, how much will he be charged?