Main content
Get ready for AP® Statistics
Course: Get ready for AP® Statistics > Unit 4
Lesson 1: Fractions, decimals, and percentagesThe meaning of percent
In this math lesson, we learn about percentages by shading 20% of a square. The square is divided into 100 smaller squares in a 10x10 grid. To represent 20%, we shade 20 of these smaller squares, which can be done by coloring two rows of 10 squares each. This visual approach helps us understand the concept of percentages. Created by Sal Khan and Monterey Institute for Technology and Education.
Want to join the conversation?
how do i solve this kind of problems: how much percent does 13 represent of an amount of 200. i understand its something as 200=100%, so 13=x% and in general, n=100%, then n-m=x%. thanks, please anyone soon! cheers.(196 votes)
Well, if it is a multiple of 100 (200 is, let's call it x) you just multiply it, however, many times it takes to get to x. You multiply 100 by 2(let's call 2 y) to get 200, so you multiply 13 times y(2).
Hope this helped. If x is not a multiple of 100, then do what I commented on another question:
Well, I am not Sal, but this is what I'd do for a whole number percent (something like 6% or 85%, not 8.7%) Divide the number that you want to 'percent' by 100. Then, take the percent (the 6 or 85) and the answer and multiply the hundredth and it together. There is your answer. (Please remember not to round and multiplying by .01 or dividing by 100 is just moving the decimal 2 places to the left.(20 votes)
What exactly is happening at2:13?(21 votes)
@2:13, he's saying that 2 out of 100 is equal to 2%.(15 votes)
How can you make percents easier to understand and make it less confusing? It there any tip, tricks, helpful suggestions, and shortcuts to learning percents in a simpler way? Please answer this question, that everyone is dying to know! :)(10 votes)
As everyone mentions 'per cent' means 'per hundred'. Say for ex, you have scored 80% in your exam, it clearly states you have got 80 marks out of total 100 marks. Suppose, the test is for 50 marks only, and you have got 25 marks out of 50, which is 25/50.
Now, if i want to find my percentage mark all i have to do is 25/50x2/2. (To make the denominator as 100, you have to multiply, both numerator and denominator with the same number(( in this ex, i have multiplied with 2)), which makes the DENOMINATOR ALONE as 100). So the resulting percentage is 50%.(18 votes)
- per cent means per 100 so 30% is 30/100 right?(13 votes)
Exactly! 30 per cent means 30/100.(9 votes)
Is a percent in anyway related to a ratio?(9 votes)
I dont know there teaching this in the ssme topic so i have no idea.(9 votes)
How will you know what percent a number will be if the number is something like 40 out of a number that isn't 100?(8 votes)
For example, if a question asked you what is the percentage of 5/25, you multiply the 25 and 5 by 4 and your numerator is the percentage.(8 votes)
how do i solve a problem with a to in it like divide 4 to 400.(7 votes)
the word "to" is used in ratios. You have a ratio of 4 to 400. It can be written in fraction form as 4/400. This is the same as 4 divided by 400.
Hope this helps.(9 votes)
- what is 12 percent of 123(9 votes)
- Rocket Skywalker got the answer but it's rounded two only 2 decimals, to have more decimals it would be: 9.75609756097561 It is just repeating the numbers ^, how you would calculate this with a calculator would be (12 / 123) * 100.(3 votes)
- What is the answer to a problem with a number bigger that 100 does it still go on top of 100?(6 votes)
- You can have percents that are larger than 100.
For example, 225% = 225/100 = 2.25(7 votes)
Is 0.4% the same as saying 4 tenths of 1 percent?
And if so, doesn’t that algebraically translate to: (4/10) times (1/100)?
But that gives us 0.004(7 votes)
2:13Video transcript
We're asked to shade 20%
of the square below. Before doing that, let's
just even think about what percent means. Let me just rewrite it. 20% is equal to-- I'm just
writing it out as a word-- 20 percent, which literally
means 20 per cent. And if you're familiar with the
word century, you might already know that cent
comes from the Latin for the word hundred. This literally means you
can take cent, and that literally means 100. So this is the same thing
as 20 per 100. If you want to shade 20%, that
means, if you break up the square into 100 pieces, we
want to shade 20 of them. 20 per 100. So how many squares have
they drawn here? So if we go horizontally right
here, we have one, two, three, four, five, six, seven, eight,
nine, ten squares. If we go vertically, we have
one, two, three, four, five, six, seven, eight, nine, ten. So this is a 10 by 10 square. So it has 100 squares here. Another way to say it is that
this larger square-- I guess that's the square that they're
talking about. This larger square is a broken
up into 100 smaller squares, so it's already broken
up into the 100. So if we want to shade 20% of
that, we need to shade 20 of every 100 squares that
it is broken into. So with this, we'll just
literally shade in 20 squares. So let me just do one. So if I just do one square, just
like that, I have just shaded 1 per 100
of the squares. 100 out of 100 would
be the whole. I've shaded one of them. That one square by itself
would be 1% of the entire square. If I were to shade another one,
if I were to shade that and that, then those two
combined, that's 2% of the entire square. It's literally 2 per 100,
where 100 would be the entire square. If we wanted to do 20, we do
one, two, three, four-- if we shade this entire row, that
will be 10%, right? One, two, three, four, five,
six, seven, eight, nine, ten. And we want to do 20, so that'll
be one more row. So I can shade in this whole
other row right here. And then I would have shaded
in 20 of the 100 squares. Or another way of thinking about
it, if you take this larger square, divide it into
100 equal pieces, I've shaded in 20 per 100, or 20%, of the
entire larger square. Hopefully, that makes sense.