do now multiply. 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...
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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
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