Fractals
Waclaw Franciszek Sierpiński, was born on March 14, 1882 in Warsaw and died on October 21, 1969 in Warsaw. He was a Polish mathematician, known for outstanding contributions to set theory (research on the axiom of choice and the continuum hypothesis), number theory, theory of functions and topology. Two well-known fractals are named after him (the Sierpinski triangle and the Sierpinski carpet), as are Sierpinski numbers and the associated Sierpinski problem. A fractal is a geometric figure that is created using iteration. Many objects in nature aren't formed of squares or triangles, but of more complicated geometric figures. Many natural objects - ferns, coastlines, etc. - are shaped like fractals.
When my students read what is above in a textbook, they still do not fully comprehend what a fractal is. So I make them do this modeling activity that is in our textbook. After doing that they understand the real meaning of doing the same thing over and over again. The activity is listed below.
Instructions
Once I got into EMAT 6690, I learned that you can do this in GSP. So I plan on doing this with my students next year as well. Click below in order to see how to make Sierpinski's Triangle in GSP.
References
http://en.wikipedia.org/wiki/Waclaw_Sierpinski