This is a way to estimate pi. Monte Carlo was the one to invent it, and this is the method implemented into scratch. Basically, when you divide the number of dots in the circle by four times the product of the number of dots, then you will get basically pi. The circle should be perfectly encrypted within a square. Here, there is a cyan outside and a red pie-like inside to help visualize.
Thanks to Monte Carlo for finding such a simple way to estimate pi.