how do you find the percent of a quantity? for example: according to a survey 10% of people report...
TRANSCRIPT
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
50%
15%
10%
25%
Favorite Flavors
VanillaChocolate ChipMintStrawberry
Let’s Review 30% of $500
Split $500 into 10 parts
1 part = $503 parts = $150
A Common Mistake
Percent to Decimal… Divide by 100… move decimal TWO places to the RIGHT
A Common Mistake
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.
Core Lesson
50%
15%
10%
25%
Flavors
Vanilla Chocolate Chip Mint Strawberry
Core Lesson
How many cones of each flavor were sold?
Option 1: Using Proportions
Van. Mint C.C. Straw.
Core Lesson
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
Core Lesson
Proportions Have Equal Within Ratios
Van.
2v=300v=150
Mint
10m=300m=30
C.C.
6.67c=300
c=45
Straw.
4s=300
S=75
Core Lesson
Proportions Have Equal Cross Products
Van.
100v=1,500v=150
Mint
100m=3,00m=30
C.C.
100c=4,500
c=45
Straw.
100s=7,500
S=75
Core Lesson
Option 2: Using equationsPercent as Decimal x Amount
Van.50% = 0.5
0.5x300=150
Mint10% = 0.1
0.1x300=30
C.C.15% = 0.15
0.15x300=45
Straw.25% = 0.25
0.25x300=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)
Extension Activities
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?
Extension ActivitiesPretend 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)
Extension Activities
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?