Do NowMultiply.

1. 0.05 20

2. 0.32 15

3. 0.06 25

4. 0.75 18

5. 0.34 76

1

4.8

1.5

Course 2

6-4 Percent of a Number

13.5

25.84

Hwk: 54

Learn to find the percent of a number.

Course 2

6-4 Percent of a Number

M7A2.a Given a problem, define a variable, write an equation, solve the equation, and interpret the solution;M7A2.b Use the addition and multiplication properties of equality to solve one- and two-step linear equations;

Course 2

6-4 Percent of a NumberThe human body is made up mostly of water. In fact, about 67% of a person’s total (100%) body weight is water. If Cameron weighs 90 pounds, about how much of his weight is water?

Part 67 = n Part100 90Whole Whole

Find the percent of each number.

Additional Example 1A: Using Proportions to Find Percents of Numbers

Course 2

6-4 Percent of a Number

30% of 5030

100= n

5030 · 50 = 100 · n

1,500 = 100n

1,500 100 100

= 100n

15 = n

30% of 50 is 15.

Course 2

6-4 Percent of a Number

When solving a problem with a percent greater than 100%, the part will be greater than the whole.

Helpful Hint

Additional Example 1B: Using Proportions to Find Percents of Numbers

Course 2

6-4 Percent of a Number

Find the percent of each number.

200% of 24200100

= n24

200 · 24 = 100 · n

4,800 = 100n

4,800 100 100

= 100n

48 = n

200% of 24 is 48.

Find the percent of each number.

Check It Out: Example 1A

Course 2

6-4 Percent of a Number

40% of 4040

100= n

4040 · 40 = 100 · n

1,600 = 100n

1,600 100 100

= 100n

16 = n

40% of 40 is 16.

Check It Out: Example 1B

Course 2

6-4 Percent of a Number

Find the percent of each number.

150% of 64150100

= n64

150 · 64 = 100 · n

9,600 = 100n

9,600 100 100

= 100n

96 = n

150% of 64 is 96.

Find the percent of the number. Check whether your answer is reasonable.

Additional Example 2A: Using Decimal Equivalents to Find Percents of Numbers

Course 2

6-4 Percent of a Number

9% of 80

9% of 80 = 0.09 · 80

= 7.2

Additional Example 2B: Using Decimal Equivalents to Find Percents of Numbers

Course 2

6-4 Percent of a Number

Find the percent of the number.

3% of 12

3% of 12 = 0.03 · 12

= 0.36

Find the percent of the number. Check whether your answer is reasonable.

Check It Out: Example 2A

Course 2

6-4 Percent of a Number

21% of 40

21% of 40 = 0.21 · 40

= 8.4

Check It Out: Example 2B

Course 2

6-4 Percent of a Number

Find the percent of the number.

6% of 18

6% of 18 = 0.06 · 18

= 1.08

Additional Example 3: Geography Application

Course 2

6-4 Percent of a Number

The estimated world population in 2001 was 6,157 million. About 40% of the people were 19 or younger. What was the approximate number of people 19 or younger, to the nearest million?

Find 40% of 6,157 million.

0.40 · 6,157

2,462.8

Check It Out: Example 3

Course 2

6-4 Percent of a Number

The estimated world population in 2001 was 6,157 million. About 60% of the people were above 19 years of age. What was the approximate number of people 19 or older,to the nearest million?

Find 60% of 6,157 million.

0.60 · 6,157

3,694.2

The number of people 19 or older was about 3,694 million.

You Try

Find the percent of each number.

1. 25% of 8

2. 40% of 110

Find the percent of each number. Check whether your answer is reasonable.

3. 150% of 96

4. 0.3% of 120

5. Whitmer Middle School has 850 students. If 42% of the students bought lunch on Monday, how many student bought lunch on Monday?

44

2

Insert Lesson Title Here

144

0.36

Course 2

6-4 Percent of a Number

357