PERCENTS

GABRIELA GUERRERO

Percent to Fractions

To Covert 20% to A Fraction

Step 1: Write down 20/100

Step 2: If the percent is a whole number, go straight to step 3

Step 3: Simplify the fraction by 20

Answer- 1/5


To Covert 0.4% to A Fraction

Step 1: Write down 0.4/100

Step 2 : Multiply both top and bottom by 10 (because there is a 1 digit after the decimal place)

Step 3: Simplify by 40

Answer- 1/25


To Convert 50% to A Fraction

Step 1: Write down 50/100

Step 2: The percent is a whole number

Step 3: Simplify by 50

Answer- 1/2


To Convert 2 3/4% to A Fraction

Fractions to Percent

Example 1 Multiplying

Step 1: Write your fraction 7/8

Step 2: Find the common factor

Step 3 :Multiply them by 12.5

Answer- 87.5%


Example 2 Dividing

Step 1 : Write down the fraction

Step 2 : Divide the numerator by the denominator

Step 3 : Move the decimal twice to the right

Answer- 87.5%


Example 3 Proportions

If 165% equals 33/20, and 16.5% equals 33/200 , then what fraction is equal to 1.65%?

The more the percent is minimized the higher the fraction denominator will get.

Percent to Decimal

Example 1

Turn 150% into a Decimal

  • When you are converting percents to decimals you will always divide by 100.
  • Move the decimal once to the left.

150 divided by 100

Answer- 1.5


Example 2

Turn 0.3% into a Decimal

  • When converting a percent that is already a decimal you only add two 0 to the left of the number.

0.3 divided by 100

Answer- 0.003


Example 3

Turn 20% into a Decimal

  • This percent will also be divided by 100
  • The decimal will be moved once to the left

20% divided by 100

Answer- 0.2


Decimal to Percent

  • For all the steps you will multiply by 100
  • Always move the decimal to the right


Example 1

Convert 0.12 into a Percent.

0.12 x 100

  • Move the decimal twice to the right

Answer- 12%e


Example 2

Convert 0.003 to a Percent.

0.003 x 100

  • Move the decimal twice to the right

Answer- 0.3%


Example 3

Convert 1.8 to a Percent

1.8 x 100

  • Move decimal

Answer-180%

Percent Proportion

Example 1

If 8 out of 20 students in a class are boys, what percent of the class is made up of boys?

In this problem, you are being asked 8 is what percent of 20?


Cross multiply and we get: 20x = 800

Divide both sides by 20 to solve for x and we get: x = 40

Answer: 40% of the class is made up of boys


Example 2
18 is 40% of what number?


Cross multiply and we get: 40x = 18(100) or 40x = 1800
Divide both sides by 40 to solve for x
We get: x = 45
Answer :18 is 40% of 45

Example 3
What is 20% of 45?


Cross multiply and we get: 100x = 45(20) or 100x = 900
Divide both sides by 100 to solve for x
We get: x = 9
Answer: 9 is 20% of 45