6-2 fractions, decimals, and percents course 2 warm up warm up problem of the day problem of the day...

6-2 Fractions, Decimals, and Percents

Course 2

Warm UpWarm Up

Problem of the DayProblem of the Day

Lesson PresentationLesson Presentation

Warm UpWrite each fraction in the simplest form.

Course 2

6-2 Fractions, Decimals, and Percents

1. 410

850

2.

3. 75100

4. 1236

5. 6. 1848

25

34

13

35

38

425

915

Problem of the DayUse the clues to find the mystery percent.

Course 2

6-2 Fractions, Decimals, and Percents

1. The product of its digits is 24.

12

3. The sum of its digits is a prime number.

83%

2. It is greater than .

Learn to write decimals and fractions as percents.

Course 2

6-2 Fractions, Decimals, and Percents

Course 2

6-2 Fractions, Decimals, and Percents

The students at Westview Middle School are collecting cans of food for the local food bank. Their goal is to collect 2,000 cans in one month. After 10 days, they have 800 cans of food. What percent of their goal have they reached?

Course 2

6-2 Fractions, Decimals, and Percents

0 200 400 600 800 1,000 1,200 1,400 1,600 1,800 2,000

0 15

25

35

45

55

00 0.2 0.4 0.6 0.8 1.0

0 20% 40% 60% 80% 100%

The model shows that 800 out of 2,000 can be written as , ,

0.4, or 40%. The students have reached 40% of their goal.

8002000

25

Write 0.7 as a percent.

Additional Example 1: Writing Decimals as Percents

Course 2

6-2 Fractions, Decimals, and Percents

Method 1: Use pencil and paper.

0.7 = 70100

= 70%

Write the decimal as a fraction with a denominator of 100.

Write the numerator with a percent sign.

710

=

Write 0.7 as a percent.

Additional Example 1 Continued

Course 2

6-2 Fractions, Decimals, and Percents

Method 2: Use mental math.

0.70 =

= 70%

Move the decimal point two places to the right and add a percent sign.

70%

Write 0.3 as a percent.

Check It Out: Example 1

Course 2

6-2 Fractions, Decimals, and Percents

Method 1: Use pencil and paper.

0.3 = 30100

= 30%

Write the decimal as a fraction with a denominator of 100.

Write the numerator with a percent sign.

310

=

Write 0.9 as a percent.

Check It Out: Example 1 Continued

Course 2

6-2 Fractions, Decimals, and Percents

Method 2: Use mental math.

0.90 =

= 90%

Move the decimal point two places to the right and add a percent sign.

90%

Course 2

6-2 Fractions, Decimals, and Percents

Write as a percent.58

58

= 5 ÷ 8

= .625

= 62.5%

Use division to write the fraction as a decimal.

Write the decimal as a percent.

Additional Example 2: Writing Fractions as Decimals

Method 1: Use pencil and paper.

To divide 5 by 8, use long division and place a decimal point followed by a zero after the 5.

8 5.00

Remember!

.625

Course 2

6-2 Fractions, Decimals, and Percents

5 ● 12.5 8 ● 12.5

Write an equivalent fraction with a denominator of 100.

=

Write as a percent.58

Additional Example 2 Continued

Method 2: Use mental math.

62.5 100

Write the numerator with a percent sign.= 62.5%

Course 2

6-2 Fractions, Decimals, and Percents

Write as a percent.35

35

= 3 ÷ 5

= 0.60

= 60%

Use division to write the fraction as a decimal.

Write the decimal as a percent.

Check It Out: Example 2

Method 1: Use pencil and paper.

Course 2

6-2 Fractions, Decimals, and Percents

3 • 20 5 • 20

Write an equivalent fraction with a denominator of 100.

=

Write as a percent.35

Check It Out: Example 2 Continued

Method 2: Use mental math.

60 100

Write the numerator with a percent sign.= 60%

Course 2

6-2 Fractions, Decimals, and Percents

Choose the most useful method of computation. Then solve.

27 out of 50 =

Using pencil and paper is the best method.

Think: 27 ÷ 50 divides evenly.

Write the decimal as a percent.

Additional Example 3: Choosing a Method of Computation

If 27 out of 50 people have the newspaper delivered to their home, what percent of these people have the newspaper delivered to their home?

2750

= 0.54

= 54%

54% of the people have the newspaper delivered to their home.

Course 2

6-2 Fractions, Decimals, and Percents

Choose a useful method of computation. Then solve.

10 out of 50 =

Mental math or pencil and paper is the best method.

Think: The denominator is a multiple of 100.

Write the decimal as a percent.

Check It Out: Example 3

If 10 out of 50 students have blue backpacks, what percent of the students have blue backpacks?

1050

= 0.20

= 20%

20% of the students have blue backpacks.

20100

=

Lesson Quiz

Insert Lesson Title Here

60%

Course 2

6-2 Fractions, Decimals, and Percents

1. Write 0.65 as a percent.

2. Write as a percent. 610

Choose the most useful method of computation. Then solve.

65%

Calculator; 45%

3. If 36 out of 80 people surveyed have been on a boat, what percent of these people have been on a boat?