Convert between fractions, decimals and percents..

Convert between fractions, decimals and percents.

Write a ratio in simplest form.

1. 6 red balloons and 6 yellow balloons were used for a party.

a) Write the ratio of red balloons to yellow balloons b) Write the ratio of red balloons to all balloonsc) Write the ratio of yellow balloons to all balloons

2. Solve the proportion:

5

2

8x

Percent:

◦Per cent => Per 100

◦Out of 100

◦ 100

◦A fraction with a denominator of 100.

To write a percent as a decimal, ◦ Divide it by 100

◦92%

To write a percent as a fraction,

◦ Put it over 100

◦92%◦92 Abc 100

Write % as Fractions & Decimals

25

23

10092 92.0

Change a Fraction to a %

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Make it 2 digits after the decimal point

◦0.60◦60%

5

3

53 6.0

1. Write 15% as a fraction2. Write 15% as a decimal.

3. Write 0.81 as a percent.

4. Write as a percent.5

1

Fractions, Decimals and Percents

Lesson 12

Which do you prefer when writing a fraction as a percent:

-rewriting the fraction with 100 in the denominator

OR

-writing the fraction as a decimal and multiplying the decimal by 100? Why?

Write the fraction as a percent.

Method 1: Rewrite as fraction . Write the percent. 70%

Method 2: Multiply decimal by 100. Convert to a decimal. Multiply by 100. 0.7·100 = 70 Write with % symbol. 70%

100

70

10

7

7.010

7

10

7

100

?

Write each decimal as a percent.

c. 1.44

Method 1: Rewrite as a fraction .

Method 2: Multiply by 100. 1.44·100 = 144%

%144100

144

100

?

Write each percent as a fraction and a decimal.

a. 25% Convert to a fraction and simplify.

Convert to a decimal. 1 ÷ 4 = 0.25 25% = = 0.25

b. 88% Convert to a fraction and simplify.

Convert to a decimal. 22 ÷ 25 = 0.88 88% = = 0.88

4

1

100

25

25

22

100

88

41

2522

Write each decimal as a percent.

a. 0.65

Method 1: Rewrite as a fraction .

Method 2: Multiply by 100. 0.65·100 = 65%

b. 0.5

Method 1: Rewrite as a fraction .

Method 2: Multiply by 100. 0.5·100 = 50%

%65100

65

%50100

50

10

5

100

?

100

?

Write the fraction as a percent.

Method 1: Rewrite as fraction . Write the percent. 40%

Method 2: Multiply decimal by 100. Convert to a decimal. Multiply by 100. 0.4·100 = 40 Write with % symbol. 40%

100

40

5

2

4.05

2

5

2

100

?

Write the fraction as a percent.

Method 1: Rewrite as fraction . 3 does not divide evenly into 100 use Method 2

Method 2: Multiply decimal by 100. Convert to a decimal. Multiply by 100. Write with % symbol.

100

?

3

1

3.03

1

3

1

100

?

3.331003.0

%3.33