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