Background information about PERCENTS!
BRAINSTORM:
What does 50% mean?
What does 25% mean?
What does 10% mean?
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10/100 is 10%
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1/10 on my test is 10%
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1 in 10 pieces
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= 10%
What is a percent?
A percent is a fraction or ratio where the denominator is 100 with a percent sign at the end.
Why is does the denominator have to be 100?
It is because percent is made up of two different words, per and cent. In French, cent means 100 so percent mean per hundred or out of 100.
How to convert decimals into percents?
Decimal --> Percent
Decimal x 100
e.g. 0.67 x 100 = 67%
How to convert percents into decimals?
Percents --> Decimal
Percent / 100
e.g 67% / 100 = 0.67
How to convert fractions into percents?
Fraction --> Percent
Numerator / denominator x 100
e.g 4/5 = 0.8 x 100 = 80%
How to convert percents into fractions?
Percents --> Fractions
Percent
---------
100
e.g 80% 80 4
------- = ------ Simplified form = ----
100 100 5
How to convert ratio into percents?
Ratio --> Fraction
Part 1 of ratio : Part 2 of ratio
Numerator: Denominator
e.g 7:3 = 7/10
Fraction --> Percent
Numerator/ Denominator x 100
e.g 7/10= 0.7 0.7 x 100 = 70%
How to convert percents into ratio?
Percents --> Ratio
Part 1 of ratio : Part 2 of Ratio
Numerator: Denominator - numerator
e.g 70% = 70:100-70 = 23:30
Three way to figuring out the percent of a number!
1st way:
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Divide the number by 100
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Then multiply the quotient by the percent number
2nd way:
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Use happy percent numbers. They usually end with a 5 or 0
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Find out the percent equivalent of the number using the 1st way.
3rd way:
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Divide the number by 10
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Divide the percent by 10
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Multiply the answer on number 1 to the answer on number 2
E.G. Find the 80% of 150
1st way:
- 150/100 = 1.5
- 1.5 x 80 = 120
2nd way:
- 50% + 30% = 80%
- (150/100 = 1.5 x 50) + (150/100 = 1.5 x 30 ) = 80%
75 + 45 = 120
3rd way:
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150/10 = 15
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80/10 = 8
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15 x 8 = 120
Problem Solving Questions:
1. Twenty-three of the Winnig Blue Bombers 44 points were scored by the offense. What percentage of the team's points were scored by the defense?
Solution:
Total points: 44 Offense points: 23
44 - 23 = 21
21 / 44 = 0.477 0.477 x 100 = 47.7 Rounded form:48
Answer: Approximately 48% of the team's points are scored by defense.
2. The sport with the greatest number of injuries annually is bicycling. Of these injuries, 12.9% of them are head injuries. Assuming there are 73 000 injuries, how many of them are head injuries?
Solution:
Total injuries: 73 000 Decimal for 12.9 % : 0.129
73 000 x 0.129 = 9 417
Answer: There are about 9 417 head injuries in bicycling.
My Percentage growing post might be able to help you! click here
My Percent scribe post might also be helpful! click here
Want to learn more about algebra? If so, have a look at my partner's page!
Maybe she can help! ----> KIM V.
Try and answer my very own quiz!
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