aim: percent course: math literacy aim: how to solve problems containing percents do now: convert:...

Aim: Percent Course: Math Literacy

Aim: How to Solve Problems Containing Percents

Do Now:

Convert:

Fraction to Decimal to Percent

4

1

8

3

10

55.

25.

375.

%50

%25

%5.37


Expressing a Fraction as a Percent

1. Divide the numerator by the denominator.

2. Multiply the quotient by 100. This is done by moving the decimal point in the quotient two places to the right.

3. Add a percent sign.

Expressing a Decimal as a Percent

1. Move the decimal point two places to the right.

2. Add a percent sign.

%254

125.


P x N = R

Percent Number Result

50% of 200 is 100

x =

RNP

N

RP

P

RN

.50 x 200 = 100


50 x 200 = ?

To find the Percent of a Number, change the Percent to a decimal then multiply by the Number to get the

Result.

What is 50% of 200?

= 100(.50)200 = R

Percent x Number = Result

% of number = resultWhat is 6% of 200?

What is 2.3% of 50?What is 42% of 80?

.06

.023

.42

x

x

x

200

50

80

=

=

=

12

1.15

33.6

Finding Result Given Percent and Number


5% of a Number is 12. Find the Number.

Percent x Number = Result 5% 12Nof is

.05 12Nx =

12)05(. N05.

12N 240N

Model Problem


To find the Percent when given the Number and Result, divide the Result by the Number

and change the fraction to a Percent.

What percent of 200 is 100?Number x Percent = Result

.50

50 10

121542 13

60 1525 18

200P = 100 P = 100/200

?

?

?

?

?

.20

.80

.31

.25.647

Finding Percent Given Number & Result

200 x = 100

?


Convert the Percent to a decimal, divide Percent into the Result to find Number

100 is 50% of what Number?

Number x Percent = Result

x .50 = 100

200

N(.50) = 100

? 6.05

45?

? 8

? 30

? 8

.30

.10

.16

.15

N = 100/.50

120

15080

200

50

Finding Number Given Percent & Result

?


Of the 560 seniors in Village High School, 476 attended the senior prom. What percent of the senior class attended the prom?

Percent Number Resultx =

RNP

N

RP

560

476P

N = 560 R = 476

85.P

What percent of the senior class . .

P = ?

Model Problem


A dealer sold a radio for $39.20, which was 40% above its cost to him. Find the cost of the radio to the dealer.

$39.20.40xx

Cost

+

+ Markup

=

= Selling Price

+ =

1.40x = 39.201.40

x = 28.00

Model Problem

1.40


In a school, there are 60 pupils who participate in a certain activity. If this is 12% of the student body, How many students are there in the school?

Percent Number Resultx =

12% 60x N Student Body

=

.12(N) = 60.12

N = 500Student Body

Model Problem

.12


A jacket regularly sells for $135. The sale price is $60.75. Find the percent decrease of the sale price from the regular price.

Finding Percent Increase or Decrease

135.00 60.65

135.00

Finding Percent Increase or Decrease1) Find the fraction for the percent increase or

decrease.

1) Find the percent increase or decrease by expressing the fraction in step 1 as a percent

amount of increase or decrease

original amount

135.00 74.25

135.00

.55 55%


At a Forest Service Youth Camp many of the workers ate some meals away from the base camp. In the dining hall at the base camp, 5% of the workers had breakfast only, 3% had lunch only, and 2% had supper only. Just 10% of the workers ate all three meals in camp. There were 5000 meals served at the base camp dining hall. No worker missed all three meals. How many workers were assigned to the Youth Camp?

Let x = the number of workers (.05) x = # eating breakfast only (.03) x = # eating lunch only (.02) x = # eating supper only (.10) x = # eating 3 meals (.80) x = # eating 2 meals

2x = 5000 x = 2500

Model Problem

1(.10x) + 3(.10x)+ 2(.80x) = 50001 meal 2 meals 3 meals


Venn Diagram

U0%

B L

Model Problem

S

5% 3%

10%

2%

B & L

L & SB & S

& & & 80%B L B S L S

250 150

100

1 1

1

2 2

2

3

250 + 150 + 100 = 500 workers 500 meals

2 or more

4500 meals = 10x x = 45

aim: percent course: math literacy aim: how to solve problems containing percents do now: convert:...

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