[Sal] I'm here with our exercise guru, Ben Eater,
[Ben] Hi Sal
[Sal] who made this exercise and now we're going to try
to work through it.
So, let's see, it says "what are the factors of 9?"
"You can resize this box with 9 dots",
the box has 9 dots
"to help you find the factors"
[Ben] Yeah, so what you're looking at,
you've got, you've got these 9 dots on the screen
and right now they're just one row of 9 dots
and if you grab that little thing on the right side of the box
and move that around to the left
[Sal] Oh, that's neat!
[Ben] you still have 9 dots, but they're arranged differently
[Sal] I see
[Ben] And so, what you can see is,
try to go get them so you have the
same number in each row
[Sal] I see, so this one, so if you have
let's see, not the same number
Oh, 3, right there!
So you could get to 9 by literally multiplying 3 rows times 3 columns
[Ben] That's right.
[Sal] and you get to 9
[Ben] So 3 is a factor
[Sal] So 3, and we'd write that in this box over here
Do we have to write 3 twice? because we have...
or is just writing 3 once?
[Ben] 3 is a factor
(overlapping) [Sal] 3 is a factor, we don't have to write [Ben] so you just put it once.
[Sal] If we wrote it twice, would it be wrong?
[Ben] Yes actually. We do mark that wrong.
[Sal] You actually do mark that wrong.
Ok, so there's 3 and 3
but there was also right when you started you had 9 and 1
[Ben] That's right, those are factors.
[Sal] and I dont have to write them in any special order?
[Ben] no, no. gotta get them all.
[Sal] And I belive that's all there is
And we can look at the other ones
And we could see, look 2 and 8, definitely that's not working out
and it's interesting for people to think
about why these aren't working out
[Ben] Right, yeah, you can't divide two into nine
[Sal] Yes, yeah, yeah, yeah
That's pretty...
And that just gets us to 1 and 9 again
And we don't want to repeat it.
[Ben] Those are the same factors
[Sal] So let's check our answer, let's see how we're doing.
There we go! We got it all right.
Let's do one more [Ben] Ok
[Sal] Let's do one more. Correct. Next question.
You can resize this box with 16 dots to help you find the factors
So 1 I'll just, 1 and 16 are factors
[Ben] 1 and 16 are factors, sure
Those are always factors
[Sal] Let me write those: 1 and 16
So let's play with this box here
So, yeah, I know, that's not working
That's not working
So I'm trying to figure out
So this is essentiall going 2 times...
2 might be a factor, if I could just
Oh, look it is!
[Ben] There it is. Two is a factor.
[Sal] Exactly, 2 rows of 8 works
So we can say 2 and 8 are factors.
[Ben] And if you think of it 2 and 8 both divide into 16
[Sal] Absolutely
[Ben] 2 divides 8 times or 8 divides 2 times
[Sal] Yes. You can see that.
You can construct
16 dots, you can divide them into 2 groups of 8
and I suspect also 8 groups of 2
[Ben] Well, you can see that
[Sal] Let's see. So that's two groups of 8
or two rows of 8
let's see, 4 - Oh, look at that! 4 times 4
[Ben] 4 times 4
[Sal] And I'll just write the 4 once
[Ben] 4 is a factor
[Sal] 4 is a factor
and then I can
and I've probably
I've already gotten 8 and 2
Now I've got 8 groups of 2 instead of two groups of 8
but they're still both factors
and you go back to 16 and 1
So, I think we're done.
[Ben] I think so!
[Sal] Let's check our answer.
[Both] Very good!
[Sal] Well, thank you. That was fun.
[Ben] Thank you
[Sal] This was very neat. Very fun to play with.
[Ben] Oh, thanks.