Solve each proportion. 1.2. 3.4. c6c6 12 15 = 21 12 7y7y = 3 + x 7 4848 = 2 + x x – 4 25 35 = 4.8...
19
Solve each proportion. 1. 2. 3. 4. c 6 12 15 = 21 12 7 y = 3 + x 7 4 8 = 2 + x x – 4 25 35 = 4.8 4 1 2 –17 Math on the Mind
-
Upload
erika-floyd -
Category
Documents
-
view
215 -
download
2
Transcript of Solve each proportion. 1.2. 3.4. c6c6 12 15 = 21 12 7y7y = 3 + x 7 4848 = 2 + x x – 4 25 35 = 4.8...
Solve each proportion.
1. 2.
3. 4.
c6
1215
= 2112
7y
=
3 + x7
48
= 2 + xx – 4
2535
=
4.8 4
12
–17
Math on the Mind
PercentsUnit 4, Lesson 11Mrs. King
Picture from hoffnermath.wordpress.com
Let’s refresh our memory:
•http://www.brainpop.com/math/ratioproportionandpercent/percents/preview.weml
What does percent mean?
•“per” means out of•“cent” means 100
▫How many years in a “century”?▫How many “cents” in a dollar?▫How many legs on a “centipede”?
Converting Percents to Decimals•To change a percent to a decimal, drop
the % sign and move the decimal point 2 places to the left
www.thericeschool.org
Convert each percent to a decimal:
▫17%
▫5%
▫23%
▫236%
▫8%
www.thericeschool.org
0.1
70.05
0.23
2.36
0.08
Converting Decimals to Percents
•To change a decimal to a percent, move the decimal point 2 places to the right and attach a % sign.
www.thericeschool.org
Convert the decimal to a percent:
▫.08 =
▫3.26 =
▫.75 =
www.thericeschool.org
8%
326%
75
%
Change to a
Decimal
Calculating Percents: The Equation Method
How much is 11% of $400?
The unknow
n!
The unknow
n!
“Equals”
“Equals”Change
to a decimal
“Multiply”
“Multiply”
$400
$400
x 11.0 40044x
Example #1
•15% of 650 is what number?
15. 650 xx5.97
Example #2
•What is 12% of 250?
x 12. 25030x
Proportions to remember!
whole
partpercent
100 of
ispercent
100
Calculating Percents: The Proportion Method
How much is 11% of $400?
of
ispercent
100
400100
11 x
x1004400
x44
Example #3
•15% of 650 is what number?
of
ispercent
100
650100
15 x
x1009750
x50.97
Example #4
•What is 12% of 250?
of
ispercent
100
250100
12 x
x1003000
x30
Percentage Problems•15 is what percent of 50?
•16 is 22% of what number?
www.thericeschool.org
Percentage Problems•91 is what percent of 364?
•What is 9.5% of 75,000?
www.thericeschool.org
Try these on your own:• 42 is what percent of
112?
• What percent of 38 is 19?
• What is 0.5% of 2350?
• http://www.quia.com/mc/499417.html
stopforfun.wordpress.com
