Thyrza and Kim V


Background information about PERCENTS! 

 

BRAINSTORM:

 

What does 50% mean?

 What does 25% mean?

What does 10% mean?

 

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:

 

  1. Divide the number by 100
  2. Then multiply the quotient by the percent number
     

 

 2nd way:

 

  1. Use happy percent numbers. They usually end with a 5 or 0
  2. Find out the percent equivalent of the number using the 1st way.

 

 

3rd way:

 

  1. Divide the number by 10
  2. Divide the percent by 10
  3. Multiply the answer on number 1 to the answer on number 2

 

 

 E.G. Find the 80% of 150

 

1st way:

 

  1. 150/100 = 1.5
  2. 1.5 x 80 = 120

 

2nd way:

 

  1. 50% + 30% = 80%
  2. (150/100 = 1.5 x 50) + (150/100 = 1.5 x 30 ) = 80%

            75 + 45 = 120

 

3rd way:

 

  1. 150/10 = 15
  2. 80/10 = 8
  3. 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!