Each of these smaller bumps are surrounded by even smaller bumps and some of these are surrounded by even smaller bumps, roughly in the same pattern. This property of self-similarity , whereby a part of the whole resembles the whole, is also a property of fractals . There is a wealth of material on the subject of fractal geometry available via the Internet. After reading this introduction to fractals the teacher might want to search the Internet to start exploring this fascinating subject further. Use these to illustrate the concept of self-similarity in natural objects.
Echinoderms are marine animals with spiny skin and five-fold radial symmetry.
Sea urchins, sand dollars, sea stars, and sea cucumbers are all echinoderms. The coastline of a continent can be considered a fractal. The teacher can draw a rough, jagged coastline on the board. If the measurements are made carefully, the total length using the smaller unit of measure will be greater. Interesting fractals can be constructed using an initiator and a generator , procedures or rules for modifying an existing object.