Multiplying 2-digit by 1-digit word problems | Khan Academy

- [Instructor] A bakery
makes 7 trays of cookies

on Friday.

Each tray holds 36 cookies.

How many cookies does the
bakery bake on Fridays?

Pause this video and
try to figure that out.

Okay, so we have 7 trays,

7 trays, and each of them has 36 cookies.

So it's really 7 sets or 7 groups of 36.

So what we really wanna
do is multiply 7 times 36.

Now there's a couple of
ways we could do this.

One way is to think about it,

"Well, that's the same thing as 7 times,

and instead of 36,

36 is the same thing as 30 plus 6."

And so here we can use
the distributive property.

We could multiply 7 times
30 and 7 times 6 to get,

and let me just do that separately.

So we are going to have, I need
to keep track of the colors.

We're gonna have 7 times 30,

and then we're gonna
add that to 7 times 6.

And so let me put the 30 here.

30 and then the 6.

And then what is that going to be?

Well, this first part right over here,

7 times 3 is 21.

So 7 times 30 is 210,

and then 7 times 6 is 42.

And so now we're going to want
to add these two together.

What's 210 plus 42?

Well, 210 plus 40 is 250
plus we have that other 2,

so this is going to be 252.

So that's one way that
you could approach it,

another way that you
could think about it is

you could take 36 and you
could multiply it by 7,

put the 7 in the one's
place right below the 6.

And then you could say,

"Alright, first this is going to be,"

let me use different colors here.

"7 times 6."

7 times 6 is 42.

And then you can think about,

"Well, what is 7 times 30?"

Well, that's 210.

And then you add everything together.

Same idea, 2 plus 0 is 2, 4
tens plus 1 ten is 5 tens,

and then you have two hundreds,

bring that down, you, we got 252 again.

And it's interesting to see
it's really just different ways

of writing the same thing.

I really did 7 times 30, plus 7 times 6,

7 times 30, plus 7 times 6.