[MUSIC] Welcome back, next to me is the head of a beautiful sunflower. If you look at this sunflower head, you see spirals, right? You see spirals spiraling clockwise, you see spirals spiraling counterclockwise, okay? We just talked about spirals, we talked about the golden spiral, we talked about the Fibonacci spiral. Here on the sunflower head we see spirals. What I want to do is count, okay? I want to count the number of spirals we see. So let's try to count together, okay? A little bit difficult to count, but let's give it a try. Let's start somewhere, so let's start here. So that's one spiral so I'm going to mark that as 1, so we can keep track. And then we'll go to the next one, that's 2, that's 3, 32, 33, and the very last one here, 34. Wow. So, this is the clockwise spirals, right? Clockwise spirals. 34. 34, what's special about 34? Well, it's a Fibonacci number. Here's our Fibonacci numbers on the bottom, 1, 1, 2, 3, 5, 8, 13, 21, 34, 34 is a Fibonacci number. So, we counted the number of spirals that are going clockwise in the sunflower head. We get 34, and 34 is a Fibonacci number. When I do this in the classroom, my students always say, coincidence. It's a coincidence, right? But let's see, we have clockwise spirals. Let me erase. We also have counterclockwise spirals here, right? We also have counterclockwise spirals. So let's do our best to try and count them. Okay, so we have counter clockwise spirals. They look a little bit easier to count in the middle. So let's start in the middle here. So let's start with this one here. Okay? And that will be our one. So that's one. Okay. And then let's count. So this one is 2, 3. And then the last one here, 21. 21. So, I count 21 spirals, Fibonacci number 1, 1, 2, 3, 5, 8, 13, 21. So I've counted 21 counterclockwise spirals, 34 clockwise spirals. I think you must find this quite interesting, right? In the sunflower head now, we've discovered the Fibonacci sequence, two numbers, 21 and 34. In the next lectures, I want to try to explain to you why the Fibonacci numbers are hidden inside of this sunflower head. Okay? I'll see you then!