Benton's Percent Post

 A percent is an equivalent fraction out of 100.

 Here is how we find percents, in this example there are 40 apples.
 The 100% of the apples is 40/40
 We will be finding 50%, 25%, 10% and 1% using ratio tables.

          50%
          %   | Apples
÷2   100 | 40 /÷
     50  |   20

         25%
            %  |  Apples
÷ 4     100  |   40   /÷
    10   |    4

        10%

         %   |  Apples
÷10     100  |    40  ÷ 10
    25   |    10

     1%
         %    | Apples

÷100      100 | 40    ÷100

     1   | 0.4

Representing Percents
1) 180%

2) 12 3/4%

3) 0.7%

 

Converting Fraction-Decimal-Percent

1) 26%

26 ÷ 100 = 0.26

0.26 x 100 = 26/100

2) 7/10

7 ÷ 10 = 0.7

0.7 x 100 = 70%

3) 0.024

0.024 x 100 = 2.4%.

2.4/100

Percents

Calculator: 60 - 80% = 12                                                      Mental Math:  60 ÷ 5 = 12

                                                                                                                       100 ÷ 5 = 20

                                                                                     

               2) 0.1% of 40

 

Calculator: 40 ÷ 100 = 0.4                                                   Mental Math: 40 ÷ 1000 = 0.4

                                                                                                                  100 ÷ 1000 = 0.1

                3) 250% of 400

Calculator: 400 x 2.5 = 1000                                             Mental Math: 400 x 2 = 800 | 400 ÷ 2 = 200

                                                                                                                  800 + 200 = 1000
                                                                                                                  100 x 2 = 200 | 100 ÷ 2 = 50

                                                                                          200 + 50 = 250

Combining Percents

4.4 Pg. 149

7. A herd of 100 caribou was moved to a new location. The population increased by 10% the first year and then increased by 20% the second year.

a) Find the population after the second year.
b) Explain why there was not a 30% increase in population over the two years.

a)The population of the caribou herd after the second year was 132

The caribou herd's numbers increased by 10% the first year creating a total number of 110 caribou. The second year, the herd of caribou, now numbering 110 in total increased it's numbers by 20% for a total of 132 caribou at the end of the second year.

b) There was not a 30% increase in population over the two years because the 100% changed instead of remaining static. The 100% increased from 100 to 110 by the end of the first year and then there was a 20% increase of the current 100% raising the 100% to 132.

Discount is the money you save.

Sale Price is what you pay at the end.

4.4 Pg.148 Show You Know

 What is the final sale price at each store? Which is a better buy? Explain your thinking.

Store A: 50% off one day only
Store B: 25% off one day followed by 25% off the reduced price the second day

Example: you want to buy a $60 pair of boots.

Store A

Since 50% is equal to half, we can just half the number in question.

60 ÷ 2 = 30

The sale price is 30$

                                                  

Store B

First Day. As 25% is equal to a quarter, we can simply divide the number by 4.

60 ÷ 4 = 15                   60 - 15= 45

The sale price is now 45$

          Second Day.  We now divide the 100% (now 45$) in 4 again.

 45 ÷ 4 = 11.25                  45 - 11.25 = 33.75

The sale price is now 33.75$

Which is a better buy?

Store A is a much better choice because they're offering a $30 pair of boots compared to Store B's price of 33.75.

Axl's Percent Post

PERCENT MEANS-  is an equivalent fraction out of 100, per(out of) cent(100)

Here how we find the percent:
Example:

There are 40 apples, the 100% of apples in 40/40
10%
50%
25%
1%

10 % means- 10 out of 100- divide 100 percent to 10 which gives you 10 and divide the 40 apples to 10 which gives you the answer of 4. (4 out of 40 or 10 out of 100)


50% means- half, part/whole, 20 out of 40 or 50 out of 100 - dived the 100 percent to 2 which gives you 50 and you also need to divide 40 apples  to 2 which gives you 20. (20 out of 40 or 50 out of 100)

25% means- quarter out of 100- divide 100 percent to 4 gives you 25 and divide 40 apples to 4 gives you 10. (10 out of 40 or 25 out of 100)

1% means- 1 out of 100- divide 100 percent to 1 gives you the answer of 1 and divide 40 apples gives you the answer of 0.4. (0.4 out of 40 or 1 out of 100)

REPRESENTING PERCENTS:

A.180%                                          

B. 0.6%

C. 12 3/8

CONVERTING PERCENTS:

Fraction to Decimal and Percent:

171/300: 171/300= 0.57/1 x 100= 57/100= 57%

Decimal to Percent and Fraction:

5.98: 5.98/1 x 100= 598/100= 598%= 598/100

Percent to Decimal and Fraction:

750%: 750%/100= 7.5/1= 7 and 5/10= 7 and 1/2

PERCENT OF A NUMBER:

20% of 60
20/100=0.2
0.2 x 60=12
Calculation:
20  x 60=1200
1200/100=12

250% of 400
25/100=2.5
2.5 x 100=1000
Calculation:
250 x 400=1000000
1000000/100=1000


0.1% of 40
0.1/100=0.001
0.001 x 40=0.004
Calculation:
o.1 x 40=4
4/100=0.004

COMBINING PERCENTS:

Question 7 page 149:

A herd of caribou was moved to a new location. The population increased by 10% first year and then increased by 20% second year.

First year:
caribou= 10%
10% + 100= 110
110/10= 1.1
1.1 x 100=  110

Second year:
caribou= 20%
20% + 100= 120
120/100= 1.2
1.2 x 100= 132

explain why there are not 30 % increase in population over  the two years?

30% was not used because 100% had change. in the first year the total of caribou was 10%, but in the second year it increased 20%, so we need to make another solution. but the total wasn't 100 anymore it change to 110.


SHOW YOU KNOW

Store A: Price 100

100 + 25%= 125
25/100= 0.25
0.25 x 125= 31.25

Store B; Price 100

100 + 50%= 150
50/100= 0.5
0.5 x 150= 75

Store A is best to buy than Store B

Chey's Percent Post

Percent means: an equivalent fraction out of 100. In French percent means "out of 100".

Here is how we find



0.6%

0.6% blow-up

180%

12 3/4 (0.75)%

12 3/4 (0.75)% blow up

2.)

       F          D          P

1.) 3/40 = 0.075 = 7.5%

       D          P          F

2.) 5.98 = 598% = 5  98/100

       P           D         F

3.) 0.3% = 0.003 = 3/1000




3.) D-P    To convert a decimal to a percent you multiply the number by 100
Ex: 0.024 x 100= 24%

P-D    To convert a percent to a decimal you divide the number by 100
Ex: 26%  ÷ 100 = 0.26

D-F    To convert a decimal to a fraction you take the decimal, say it, and write in fraction form.
Ex: 0.024 (say it = twenty four thousandths/ 24 out of 1000) 24/1000

F-D    To convert a fraction to a decimal you take the fraction, say it, and write in decimal form.
Ex: 7/10 (say it = seven out of ten/ seven tenths) 0.7

P-F     To convert a percent to a fraction you write the percent as a fraction with 100 as the denomenator,
and then put it lowest terms or if it is "top heavy" you make it a mixed fraction instead of an improper fraction
Ex: 24% = 24/100   24/100 = 6/25      Ex: 180% = 180/100    180/100 = 1 8/10

F-P    To convert a fraction to percent you divide the numerator by the denomenator, then you take the answer and multiply it by 100.

4.)       MENTAL MATH                                                        CALCULATOR 
                  %    |     #                                                                    60/5 = 12
                 100  |     60
         /5      20   |     12     /5


                %  |     #    
              100 |    40     
/1000      0.1 |    0.04     /1000                                                  40/1000 = 0.04


                        



         %    |     #                        %    |      #     
        100  | 400                       100  |   400
/2        50 | 200  /2       *2       200  |   800       *2                                 400/2 = 200

50% + 200% = 250%            200 + 800 = 1000                                  400 *2 = 800
                                250%=1000                                                        200 + 100 = 1000






5.) Discount is the money you save. Sale Price is what you pay after you subtract the discount off of the original price. Total Price With Taxes is the original price with a percentage called taxes added on. In percents it is more than 100%. Ex A pair of boots is 59.99 and the tax is 13%, you are paying 113% of the original price of the boots. To find the Total Price With Taxes you find the percentage being used for taxes and then you add that too the original price.

50% off is a better deal than 25% off an already reduced price. This is because adding the 25% off's together does not make 50% off because it is 25% off the original price and then 25% off the reduced price, which is new 100%. Ex. A shirt at Walmart is $10.00 and is on sale for 50% off. A shirt at Old Navy is $10.00 and is on sale for 25% off. The next day the shirts are still on sale except the shirt from Old Navy is now an additional 25% off. Which is the better buy?

10/2 = 5 $10.00-$5.00 = $5.00 Walmart Sale Price = $5.00
($5 is the Discount and when you subtract it from the original price ($10) you get the sale price, which is $5)
10/4 = 2.50 $10.00-$2.50 = $7.50       7.50/4 = 1.875 ($1.88) 7.50-1.88 = $5.62
Old Navy Sale Price = $5.62
($4.38 is the Discount and when you subtract from the original price ($10) you get the sale price, which is $5.62) Walmart is the better buy.

Lizley's Percent Post

Percent means
-percent means "out of a hundred"

*This is how to find the percent of a fraction:
 9   X 10  =  90
10  X 10  = 100
= 90%

But why 100?
-100 is used because its easy to use/its a friendly number.

*Meanings

100% - means all, everything, 100 , 100%
                                              100
                                    
50% - means half,  50  , 1 , 50%
                            100   2

25% - means half 50, 25 %, 25 , 100
                                            100    4

10% - means 100 ,  10 , 10%
                      10    100

1% - means 1 out of a 100,  1   , 100 , 1%
                                          100     1

But how about 205% ?
-it is improper/top heavy
-it means 2 holes
- 205
  100

Representing Percent

 180%

100

80

0.6%

                                               

12 3

     8

                                 

How to convert from Decimals to Percents to Fraction

1) 26%

-To convert it to become a decimal, you need to divide 26 to 100.

26 ÷ 100 = 0.26

to be simpler, just move the decimal point two spaces to the left.

26. → 0.26

-To convert it to fraction, you just make it 26/100 and simplify it to 13/50

2) 7/10

-To convert it to percent, you just need to divide the numerator to the denominator. Then move the decimal point two spaces to the right.

7 ÷ 10 = 0.7

0.7 → 7. = 7%

-To convert it to decimal is just dividing the numerator to the denominator.

7 ÷ 10 = 0.7

3) 0.024

-To convert decimal to percent, you just need to move the decimal point 2 spaces to the right.

0.024 → 2.4%

-To convert decimal to fraction, you need to convert it to decimal, and count the decimal places. The number before the decimal point will be the whole number.

2.4 → 2 4/10 = 2 2/5

How to get the percent of a number

      
 20% of 60 :

Mental
       %  | #                                                                                                      
÷5 100 | 60  ÷5                                  
       20 |12

Calculator
20 ÷ 100 = 0.20 = 0.2
0.2 x 60 = 12

20% of 60 is 12

                           
0.1% of 40:

Mental
               % | # 
÷10      100 | 40    ÷ 10
÷100      10 | 4      ÷ 100
             0.1 | 0.04

Calculator
 0.1÷100=0.001
0.001 x 40 = 0.04

0.1% of 40 is 0.04

250% of 100

Mental

                 %| #
             100 | 100

÷ 100       1  | 1         ÷100

x 250     250|250       x250

Calculator

100 ÷ 100 = 1

1 x 250 = 250

 

Combining Percents

Discount  - What you save

Sale Price - What you pay

 _____________________

Problem:

 A herd of 100 caribou was moved to a new location. the population increased by 10% the first year and then increased by 20% the second year.

 

a) find the population after the second year.

1. You have to find the 10% of 100 to know the population that increased the 1st year.

 

 

2. Then, add it to 100.

 

100 + 10 = 110

 

3. Find out the 20% of 110, and add it to 110, because 110 is our new total.

 

110 ÷ 100 = 1.1

1.1 x 20 = 22

110 + 22 = 132

 

 



b) Explain why there was not a 30% increase in population over the two years.

If the percent had changed, the final answer would change too.

Andrei's Percent

Percent is another way of writing a ratio when the second term of the ratio is 100.  Percent comes from the Latin words pars per centum meaning parts per hundred. We use % to express percent.

Example:
18/100 = 18%

25/100 = 25%

 If the denominator is not 100,  multiply the numerator and the denominator with the same number which will make the denominator equal to 100.

Example:

4/5 =4/5 x 20/20 = 80/100  or 80%

1/2 = 1/2 x 50/50 = 50/100 or 50%   means half of whole

1/10 = 1/10 x 10/10 = 10/100 or 10%  means 1 part of a whole

1/4 = 1/4 x 25/25 = 25/ 100 or 25%  means quarter of a whole

3. Converting Percent to Decimal to Fraction

Fraction to  Decimal  to  Percent 3/40         =     0.075   =    7.5% to decimal divide 3/40 = .075 to percent move the decimal point 2 places to the right and add the percent % sign 0.075 = 7.5% Decimal  to Percent to  Fraction 0.0064     =   0.64%      =  0.0064/10000  or       4/625                                                               to percent move the decimal point two places to the right and add the percent sign % 0.0064 = 0.64% to fraction multiply both the top and bottom by 10 for every number after the decimal point 0.0064/1  x 10 000 /10 000 =  64/ 10 000  or 4/625 Percent to Decimal  to  Fraction 75%   =       0.75        =     75/100 or 3/4 to decimal move the decimal point 2 places to the left and remove the % sign 75% = 0.75 to fraction 75/100 = 3/4 4. Finding Percent of  a number     solve:                                                                    a. 20% of 60       Mental Math                                                                   Calculator       100% of 60 is 60                                                          convert 20% to decimal       10% of 60 is 6                                                               20%  is 0.20        20% is 10% + 10%                                                      multiply 0.20 by 60        10% + 10% = 6 + 6                                                      0.20 x 60 = 12         20% = 12    b.  0.1%          Mental Math                                                                Calculator        100% of 40 is  40                                                        convert 0.1% to decimal        10% of 40 is  4                                                             0.1% is .001        1% of 40 is  0.4                                                            multiply .001 by 40         0.1% of 40 is  0 .04                                                     0.001 x 40 = 0.04         0.1 % of 40  = 0 .04    c.  250% of 400        Mental Math                                                                 Calculator        100% of 400  is 400                                                    convert 250% to decimal        50% of 400 is 200 ( 400/2)                                         250%  is 2.50        250% is 100% + 100% + 50%                                   multiply 2.50 by 400        100% + 100% + 50% =  400 + 400 + 200                2.50 x 400 = 1000        250% of 400  = 1000 5. Combining Percents    * Discount is  a deduction from the usual cost of something.    * Sale Price is the price of a good service that is being offered at a discount.    * Total price with taxes is the total amount and tax charges for all items being purchased. Example:     * A herd of caribou was moved to a new location.  The population increased by 10% the first       year and then increased by 20% the second year.       a.  Find the population after the second year.       b.  Explain why there was not 30% increase in population over  two years.     Solution:          a.  Population of caribou is 100            increase in first year    is  10%                  10%  of 100   or  0.10  x 100 = 10            population of caribou after one year is 100 + 10 = 110           New population of caribou ( after one year)  is 110            increase  in second year is  20%                    20% of 110 or  0.20  x  110 = 22            population of caribou after second year is 110 + 22 = 132                             b.  There was not a 30% increase in population over two years because after a year, the              population increased by 10% , it became 110 and this new population was increased               by 20% which gave a total population of 132 caribou after the second year.              If population was increased by 30% over two years,  the original population 100 will be               increased by 30%  which will result to 130 population. *Show you know*      What is the final price at each store.  Which is the better buy?   Explain your thinking.       Store A:  50% one day only       Store B:  25% off one day, followed by 25% off the reduced price the second day.      Example:      Store A :  50% of $200 (one day only)                       0.50 x 200 = 100     Find the discount price:                       200 - 100 = 100     The discount price is $100.     Store B:  25% discount of $200 on the first day                     0.25 x 200 = 50      Find the discount price                      $200 - 50 = 150      The discount price after the first day is $150.            The discount  on the sale price the second day is  25% of $150.                    0.25 x 150 = 37.5       Find the discount price:                    $150 - 37.5 = $112.50        The final discount price after the second day is $ 112.50.      *** Store A gives the better buy than store B.  The 25% discount followed by another 25%            is not the same as 50% discount from the original price because the discount on the             second day is only 25% of  $150 and not 25% of $200.       The original price is $200.  The selling price after two 25% discount is $112.50                    $200 - $112.50 = $87.50                    $87.50 ÷ 200 = 0.4375  or  0.44  which is 44%         ***  The total discount offered by store B is 44% which is less than 50% discount offered             by Store A, therefore Store A gives the better buy.            Video that will help us understand how to find a percent of a number.