Sunday, November 17, 2013

Jayson's Percent Post

Hi this is my percent post:

1.
a) to find 50% of a number, you divide the number by 2 to get your answer.
b)to find 10% of a number, divide the number by 10 to get your answer.
c)to get 1% of a number, divide your number by 100 to get your answer.
d)to get 25% of a number, you divide your number by 4, or if you already know 50%, divide that by 2.

A percent is a number out of a hundred or a whole.

2.
 180%
 12 3/4%

0.7%










3. 

26%
To convert 26% to a decimal, you have to divide the number by 100

ex. 26% ÷ 100 = 0.26

To get the fraction of 26%, first you covert it to a decimal,then say the number as it is.

ex: 0.26 pronounced as ----------> twenty-six hundredths -------------> 26/100--------------> twenty- six out of a hundred.


7/10
To convert a fraction to a decimal, simply divide the numerator (top number) to the denominator (bottom number)

ex: 7/10 -----------> 7 ÷ 10= 0.7

To convert a fraction to a percent, you find the decimal number first then you multiply that by a hundred, then just remember to add the percent sign at the end.

ex: 0.7 x 100 = 70%


0.024
To convert a decimal to a percent ,you take your decimal and you multiply it by 100.

ex: 0.024 x 100 = 2.4

To convert your decimal to a fraction, take your decimal number (0.024) and say it.

ex: 0.024 ----------> twenty-four thousandths ---------->24/1000 -----------> twenty-four out of one thousand.

4.
20% of 60=12

Mental: 10% of 60= 6
            20% of 60=12

Calculator: 20% ÷ 100 = 0.2
                 0.2 x 60 = 12

0.1% of 40 =

Mental: 100÷100=1
            40÷100= 0.4
Calculator: 40÷100= 0.4

250% of 400

Mental: 100% of 400= 400
            200% of 400= 800
            50% of 400= 200
            250% of 400= 10 000
Calculator: 100% x 2 = 200%                       400 x 2 = 800
                 100 ÷ 2= 50%                             400 ÷ 2 = 200
                 200% + 50% = 250%                 800  + 200= 10 000


5.
Question 7 on page 149
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 on the second year.

10% of 100= 10
100 + 10 = 110

10% of 110 =  11
20% of 110 = 22
110 + 22 = 132

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

There isn't a 30% increase in population over the two years because they only add 10% each year.
It's only been 2 years and that would result in an increase of only 20% because they add 10% each year.
If it's been 30 years, then it would increase by 30%