for its collection of videos,

so before I go any further,

let me show you a little bit of a montage.

(Video) Salman Khan: So the hypotenuse is now going to be five.

This animal's fossils are only found in this area of South America --

a nice clean band here --

and this part of Africa.

We can integrate over the surface,

and the notation usually is a capital sigma.

National Assembly: They create the Committee of Public Safety,

which sounds like a very nice committee.

Notice, this is an aldehyde,

and it's an alcohol.

Start differentiating into effector and memory cells.

A galaxy. Hey, there's another galaxy.

Oh look, there's another galaxy.

And for dollars, is their 30 million,

plus the 20 million dollars from the American manufacturer.

If this does not blow your mind,

then you have no emotion.

(Laughter)

(Applause)

SK: We now have on the order

of 2,200 videos

covering everything from basic arithmetic

all the way to vector calculus

and some of the stuff you saw there.

We have a million students a month using the site,

watching on the order of 100 to 200,000 videos a day.

But what we're going to talk about in this

is how we're going to the next level.

But before I do that,

I want to talk a little bit about really just how I got started.

And some of you all might know,

about five years ago I was an analyst at a hedge fund,

and I was in Boston,

and I was tutoring my cousins in New Orleans, remotely.

And I started putting the first YouTube videos up

really just as a kind of nice-to-have,

just a supplement for my cousins --

something that might give them a refresher or something.

And as soon as I put those first YouTube videos up,

something interesting happened --

actually a bunch of interesting things happened.

The first was the feedback from my cousins.

They told me

that they preferred me on YouTube than in person.

(Laughter)

And once you get over the backhanded nature of that,

there was actually something very profound there.

They were saying

that they preferred the automated version of their cousin

to their cousin.

At first, it's very unintuitive,

but when you actually think about it from their point of view, it makes a ton of sense.

You have this situation

where now they can pause and repeat their cousin,

without feeling like they're wasting my time.

If they have to review something

that they should have learned a couple of weeks ago,

or maybe a couple of years ago,

they don't have to be embarrassed and ask their cousin.

They can just watch those videos. If they're bored, they can go ahead.

They can watch it at their own time, at their own pace.

And probably the least appreciated aspect of this

is the notion that the very first time,

the very first time

that you're trying to get your brain around a new concept,

the very last thing you need

is another human being saying, "Do you understand this?"

And that's what was happening with the interaction with my cousins before,

and now they can just do it

in the intimacy of their own room.

The other thing that happened is --

I put them on YouTube just --

I saw no reason to make it private,

so I let other people watch it,

and then people started stumbling on it,

and I started getting some comments and some letters

and all sorts of feedback

from random people from around the world.

And these are just a few.

This is actually from one of the original calculus videos.

And someone wrote just on YouTube --

it was a YouTube comment:

"First time I smiled doing a derivative."

(Laughter)

And let's pause here.

This person did a derivative

and then they smiled.

And then in a response to that same comment -- this is on the thread.

You can go on YouTube and look at these comments --

someone else wrote: "Same thing here.

I actually got a natural high and a good mood for the entire day.

Since I remember seeing

all of this matrix text in class,

and here I'm all like, 'I know kung fu.'"

(Laughter)

And we get a lot of feedback all along those lines.

This clearly was helping people.

But then, as the viewership kept growing and kept growing,

I started getting letters from people,

and it was starting to become clear

that it was actually more than just a nice-to-have.

This is just an excerpt

from one of those letters.

"My 12 year-old son has autism

and has had a terrible time with math.

We have tried everything,

viewed everything, bought everything.

We stumbled on your video on decimals and it got through.

Then we went on to the dreaded fractions. Again, he got it.

We could not believe it.

He is so excited."

And so you can imagine,

here I was an analyst at a hedge fund.

It was very strange for me to do something of social value.

(Laughter)

(Applause)

But I was excited, so I kept going.

And then a few other things started to dawn on me.

That, not only would it help my cousins right now,

or these people who are sending letters,

but that this content will never go old,

that it could help their kids

or their grandkids.

If Isaac Newton

had done YouTube videos on calculus,

I wouldn't have to.

(Laughter)

Assuming he was good. We don't know.

(Laughter)

The other thing that happened --

and even at this point, I said, "Okay, maybe it's a good supplement.

It's good for motivated students.

It's good for maybe home schoolers."

But I didn't think it would be something

that would somehow penetrate the classroom.

But then I started getting letters from teachers.

And the teachers would write, saying,

"We've used your videos to flip the classroom.

You've given the lectures, so now what we do ... " --

and this could happen in every classroom in America tomorrow --

" ... what I do is I assign the lectures for homework,

and what used to be homework,

I now have the students doing in the classroom."

And I want to pause here for --

(Applause)

I want to pause here for a second,

because there's a couple of interesting things.

One, when those teachers are doing that,

there's the obvious benefit --

the benefit that now their students

can enjoy the videos in the way that my cousins did.

They can pause, repeat at their own pace,

at their own time.

But the more interesting thing is --

and this is the unintuitive thing when you talk about technology in the classroom --

by removing the one-size-fits-all lecture from the classroom

and letting students have a self-paced lecture at home,

and then when you go to the classroom, letting them do work,

having the teacher walk around,

having the peers actually be able to interact with each other,

these teachers have used technology

to humanize the classroom.

They took a fundamentally dehumanizing experience --

30 kids with their fingers on their lips,

not allowed to interact with each other.

A teacher, no matter how good,

has to give this one-size-fits-all lecture

to 30 students --

blank faces, slightly antagonistic --

and now it's a human experience.

Now they're actually interacting with each other.

So once the Khan Academy --

I quit my job

and we turned into a real organization --

we're a not-for-profit --

the question is, how do we take this to the next level?

How do we take what those teachers are doing

to their natural conclusion?

And so what I'm showing you over here,

these are actual exercises

that I started writing for my cousins.

The ones I started were much more primitive.

This is a more competent version of it.

But the paradigm here is, we'll generate as many questions as you need

until you get that concept,

until you get 10 in a row.

And the Khan Academy videos are there.

You get hints, the actual steps for that problem,

if you don't know how to do it.

But the paradigm here, it seems like a very simple thing:

10 in a row, you move on.

But it's fundamentally different than what's happening in classrooms right now.

In a traditional classroom,

you have a couple of homework,

homework, lecture, homework, lecture,

and then you have a snapshot exam.

And that exam, whether you get a 70 percent, an 80 percent,

a 90 percent or a 95 percent,

the class moves on to the next topic.

And even that 95 percent student,

what was the five percent they didn't know?

Maybe they didn't know what happens when you raise something to the zero power.

And then you go build on that in the next concept.

That's analogous to

imagine learning to ride a bicycle,

and maybe I give you a lecture ahead of time,

and I give you that bicycle for two weeks.

And then I come back after two weeks,

and I say, "Well, let's see. You're having trouble taking left turns.

You can't quite stop.

You're an 80 percent bicyclist."

So I put a big C stamp on your forehead

and then I say, "Here's a unicycle."

But as ridiculous as that sounds,

that's exactly what's happening

in our classrooms right now.

And the idea is you fast forward

and good students start failing algebra all of a sudden

and start failing calculus all of a sudden,

despite being smart, despite having good teachers,

and it's usually because they have these Swiss cheese gaps

that kept building throughout their foundation.

So our model

is learn math the way you'd learn anything,

like the way you would learn a bicycle.

Stay on that bicycle. Fall off that bicycle.

Do it as long as necessary until you have mastery.

The traditional model,

it penalizes you for experimentation and failure,

but it does not expect mastery.

We encourage you to experiment. We encourage you to failure.

But we do expect mastery.

This is just another one of the modules.

This is trigonometry.

This is shifting and reflecting functions.

And they all fit together.

We have about 90 of these right now.

And you can go to the site right now. It's all free. Not trying to sell anything.

But the general idea is that they all fit into this knowledge map.

That top node right there, that's literally single digit addition.

It's like one plus one is equal to two.

And the paradigm is, once you get 10 in a row on that,

it keeps forwarding you to more and more advanced modules.

So if you keep further down the knowledge map,

we're getting into more advanced arithmetic.

Further down, you start getting into pre-algebra and early algebra.

Further down, you start getting into algebra one, algebra two,