Daily Problem

• There are an estimated 53 billion dogs in the U.S. For every 20 people who own a dog, 19 pet and hug their dog daily. Write the fractions of people who pet and hug their dogs daily as a decimal.

1920

20 19.0

0. 9

-180

10

0

0

5

100

Fractions, Decimals, and Percents

Unit One CurriculumChapter 5 Text

GLE’s

• #1 Recognize and compute equivalent representations of fractions, decimals, and percents

• #2 Compare positive fractions, decimals, percents, and integers using symbols

• #9 Determine when an estimate is sufficient and when an exact answer is needed in real-life problems using decimals and percents

Objectives

• Write fractions as percents and percents as fractions

• Write percents as decimals and decimals as percents

TLW:

Key Terms to Know

• Ratio- a comparison of two numbers by division

• Percent- when a ratio compares a number to 100

• Multiple- the product of a number and any whole number

• Least Common Denominator- the least common multiple of two denominators

Ratio

• Comparison of two numbers by division.

• Can be written in several different ways– 34 out of 100– 34:100– 34/100

• Ratios show relationship between two numbers such as a sub-group to a general group

Percent

• A ratio with a denominator of 100

• Means per 100

• Identified by the symbol: %

• Used in Statistics to represent data

Connecting Fractions to Percents• A fraction can be represented as a percent

by finding its equivalent fraction with a denominator of 100

4

5

x 20

x 20

80

100=

When the denominator is 100 , the numerator is the percent. So, in this case…

80%A fraction is a ratio, so 4:5 can also be expressed as…

Percents back to Fractions

• If a percent is the numerator of a fraction that has a denominator of 100…it should be obvious that to change a percent to a fraction…put it over 100.

48%100

Numerator

48

*Then simplify your fraction!!!

÷ 4

÷ 4

GCF

12

25=

Use Percent to Solve a Problem

• A student scored 16 out of 20 points on a quiz. Determine the student’s grade for the quiz by finding the percent.

16:20

x 5

x 5

16

20

80

100=

percent 80%

Connecting Decimals to Percents• A decimal can be represented as a percent

by moving the decimal two places to the right.

0 28. 28%

Percents back to Decimals

• To change a percent back to a decimal…move the decimal back to the left two places.

28.% 0.28