Brady: "Careful, the Droste box."
Thank you.
Hey, it's Brady Haran's birthday. By way of wishing him happy birthday,
I made him a cake. So let's give him a quarter of this cake.
Let's just say oh, you know, let's divide this up.
Brady: "It's a square, is it?"
It's a square eight inches on a side, give or take. Let's divide it up
and put a few Sprinkles over here. There you go, Brady. I'll put a candle right in the middle.
Where's my candle? What'd I do with the candle? Let's cut it right along here,
along here.
I made sure that this is halfway along there and over there. Yep, we got a quarter of this out of here.
Okay, now I've got a cake. Oh, it's a square cake missing one corner. My wife's coming home.
I've got two kids coming home and me.
How can I divide
this remaining
part of the cake
into four equal parts?
That will make
both of my kids, my wife and me happy? Look easy to do it in three parts.
One, two, right? One part, two part, three part.
How do you divide this up into 4 equal parts?
I told you that was gonna happen!
I warned you. My wife's gonna kill me
for good reason.
Didn't just warn me, it happened. Twice. So I'm an idiot.
Brady: "Oh no!
"How did the fire get to the cocoa?"
It burned its way through here, and you can see the cocoa itself is burning.
What shape is this in? It's sort of an L-shape.
What if I reduce that L?
And repeat, repeat it like this, and then a cut here,
a cut here.
I've now got four pieces that are nominally the same.
One L-Shape here,
one L-Shape here,
one L-Shape here, and then one over here. They're all the same size,
and, if you think about it,
we can use recursion to do the same thing for Brady's piece
The whole cake was four, the whole cake was four, Brady got one full unit.
I get three-quarters of a unit, my wife gets three quarters of a unit,
one kid gets three quarters of a unit, the other kid gets three quarters of a unit.
And it's all right because Brady got the biggest piece.
Brady: "I've already had a little bit, Cliff
"I've already been eating it."
The cocoa itself is burning.
Brady: "I warned you. I said don't put the candle."
I know! Hey, you did more than just warn me. So how do I get rid of this?
Geez it's hot! It's on fire!
Brady: "It's not going to be like a bomb or something is it 'cause it's all like packed in?"
Yes, exploding cocoa has been this huge problem across the ages!