Download Whole Numbers - Pacoima Charter School

Today we will compute a given
percent as a part of a whole number.
compute – figure out an answer using
math
percent – per one hundred (100)
whole number –numbers that start with
zero and have no decimals or fractions
Concept
When you take a test your score is
shown as a percent.
For example, lets say you take a math test
that has 100 questions on it. If you score
70%, the number of answers correct is 70.
APK
Percent
Percent means per hundred. It is
another way of saying, “out of one
hundred.”
CD
Whole Numbers
Whole Numbers are numbers that start with
zero and do not have decimals or fractions.
CD
Books!
I have read
95% of the
books out of
my 100-bookcollection.
95 books
CD
How to compute a given percent of
a whole number.
• 1. When you see a percent problem you know
when you read “of” in the problem you
multiply.
• 2. Change your percent to a decimal and then
move it two places to the left.
• 3. Multiply just like a regular decimal
multiplication problem.
• Place the decimal point 2 places to the left in
your answer.
How to Find the Percent of a
Whole Number
•
The first thing to remember is “of”
means multiply in mathematics.
of = x
Copyright © 2000 by Monica Yuskaitis
How to Find the Percent of a
Whole Number
•
Step 1 - When you see a percent
problem you know when you read
“of” in the problem you multiply.
25% x
of 200
Copyright © 2000 by Monica Yuskaitis
•
How to Find the Percent of a
Whole Number
Step 2 – Change your percent to a
decimal and then move it two places
to the left.
.25%
. x 200
Copyright © 2000 by Monica Yuskaitis
•
How to Find the Percent of a
Whole Number
Step 3 – Multiply just like a regular
decimal multiplication problem.
200
x .25
100
+400
0
5000
Copyright © 2000 by Monica Yuskaitis
•
How to Find the Percent of a
Whole Number
Step 4 – Place the decimal point 2
places to the left in your answer.
200
x .25
100
+400
0
5000
.
Copyright © 2000 by Monica Yuskaitis
What is the percent of this number?
.20. % xof 820
820
x .20
000
+1640
1640
.
Copyright © 2000 by Monica Yuskaitis
1. When you see a
percent problem you know
when you read “of” in the
problem you multiply.
2. Change your percent to
a decimal and then move it
two places to the left.
3. Multiply just like a
regular decimal
multiplication problem.
Place the decimal point 2
places to the left in your
answer.
What is the percent of this number?
725
.40. %1xof
2
725
x .40
000
+2900
29000
.
Copyright © 2000 by Monica Yuskaitis
1. When you see a
percent problem you know
when you read “of” in the
problem you multiply.
2. Change your percent to
a decimal and then move it
two places to the left.
3. Multiply just like a
regular decimal
multiplication problem.
Place the decimal point 2
places to the left in your
answer.
Multiply the decimal equivalent of the
percent with the whole number.
75% of 4
2
.75
x 4
30
.0
1. When you see a
percent problem you know
when you read “of” in the
problem you multiply.
2. Change your percent to
a decimal and then move it
two places to the left.
3. Multiply just like a
regular decimal
multiplication problem.
Place the decimal point 2
places to the left in your
answer.
What is 50% of a dozen(12)?
50% = ½ = .50
Therefore:
(dozen)
12
X
.50 =
6
.50
12
x
10 0
+ 500
.
600
What is 40% of 20?
40% = 40/100 = .40
Therefore:
20 X
.40 =
8
.40
20
x
00
+8 0 0
.
800
What is 3% of 36?
3% = 3/100 = .03
Therefore:
36 X 0.03 = 1.08
1
.03
36
x
18
+0 9 0
.
108
Why is understanding percent of a
whole number important?
• You will know the relationship between any
whole number and a percent.
• You will know how a percent translates into
decimals.
• What are other reasons why it is important to
know how to understand
IMP
What is 4% of 56?
4% = 4/100 = .04
Therefore:
56 X 0.04 = 2.24
1. When you see a
percent problem you know
when you read “of” in the
problem you multiply.
2. Change your percent to
a decimal and then move it
two places to the left.
3. Multiply just like a
regular decimal
multiplication problem.
Place the decimal point 2
places to the left in your
answer.
2
.04
56
x
24
+ 2 00
.
224
What is 12% of 144?
12% = 12/100 = .12
Therefore:
144
X
.12 =
17.28
1. When you see a
percent problem you know
when you read “of” in the
problem you multiply.
2. Change your percent to
a decimal and then move it
two places to the left.
3. Multiply just like a
regular decimal
multiplication problem.
Place the decimal point 2
places to the left in your
answer.
.12
144
x
48
480
+1 2 0 0
.
1728
Let’s review what we learned about computing a given percent
as a part of a whole number?
• What does percent mean?
• How do you write 10%
as a decimal?
• How do you compute a
given percent as a part of
a whole number?
“out of a
hundred”
0.10
Multiply the
whole number
with the decimal
equivalent
of the percent.