Now you try!Write the fraction as a percent.

1. 11/20 2. 4/25 3. 5/100

55% 16% 5%

PERCENTS

by: Miss Perri

Real World Applications

Shopping Discounts

“The entire store is 25% off”

Restaurant Tips“While dining out 15%-20% is the social norm for gratuity”

Demographics“At JTL, 36% of the students are

in the 8th grade.”

Sales Tax“In PA there is a 6% sales

tax.”

All sports“Derek Jeter’s career

batting average is .312 or 31.2%”

Test Grades“Charlie received a 85% on

his last Math test”

All Statistics

“Over 25% of teens have been bullied

repeatedly through text messages and

the internet.”

Nutrition Facts“If you eat a snickers bar

you will consume 25% of

your allotted daily intake for fats”

PERCENT

Percent comes from the

Latin per centum, or

“per hundred”

is a ratio whose denominator is 100.

25% is 25 “per hundred”

orthe fraction 25/100

The symbol for percent is %

This is one whole square.

One WholeSquare

Divide the square into 100 even pieces.

So 100% of the square is shaded

orange. So 100% and 1

Whole are the same thing.

Everyone of the 100 pieces is shaded

Percents

Write 29% and 45% as fractions in simplest form.

p%

Fractions

p . 100

simplify

29%= 29 . 100

45%= 45 = 9 . 100 20

÷5

÷5

Now you try!Write the percent as a fraction in simplest

form

1. 51% 2. 25% 3. 80%

51 .100

14

45

Fraction Percent

Multiply numerator and denominator by the same factor to make the denominator 100.When in form p/100, then p is the percent.

Write 7/10 and 3/5 as a percent.

7 . 10

×10

×10

70 100

70%= = 3 . 5

×20

×20

60 100

60%= =

Writing Probability as a Percent

1. Find Probability and put into fraction form2. Convert from fraction to percent

Prize: A radio station randomly selects 1 of 5 finalists for a prize. You are one of the finalists. What is the probability

that you will win? Write your answer as a percent.

Solution: There are 5 possible outcomes, and 1 is favorable.

P(you win) =1/5 (write probability as a fraction)

= 20% (write fraction as a percent)

Answer: The probability that you will win is 20%.

Now you try!A computer randomly generates an integer from 1 to 10. Find the probability of the given event . Write your answer as a percent.

1. P(5) 2. P(odd #) 3. P(prime #)

1/10 = 10 % 5/10 = 50 % 5/10 = 50 %

Finding the percent of a number

1. Take percentage and convert to fraction2. Put fraction in simplest form3. Multiply fraction by Number

Tortoises: A desert tortoise can go a year or more without drinking water. When it does drink, its body weight can increase by 40%. Suppose a desert tortoise weighs 15 pounds after a long period without water. How many pounds can the tortoise gain when it drinks.

40% 40/100 2/5 2/5(15) 6 pounds

Now you try!Find the percent of a number.

1. 25% of 36 2. 70% of 70

9 49

SUMMARYA percent is a ratio whose number is over ______ ?

Explain how you would re-write 13/25 as a percent.

100

You would multiply the numerator and denominator both by 4.Then you would get 52/100. 52% would be

your answer.

Name: __________________________ Date: _________________

Percents to Fractions

Fractions to Percents

Writing Probability as a

Percent.

Finding the percent of a

number. Round to nearest

tenth.

Directions: Please complete each section and circle your final answer. Show your work

1. 36%

2. 3%

3. 90%

4. 50%

1. 1/5

2. 2/5

3. 4/100

4. 8/25

A computer randomly generates and integer from 1-51. P(4)

2. P(odd)

3. P(a number divisible by 2)

4. P(prime #)

1. 60% of 12

2. 15% of 100

3. 30% of 300

4. 50% of 400