Pine cones found throughout British Columbia and around the world have a very interesting connection to a very famous set of numbers. This set is called Fibonacci numbers.
The spirals on a pine cone are leaves of a sort. Usually, you think of leaves as soft, but pine cone leaves are hard and packed together. These hard leaves protect the pine cone in all sorts of weather.
The name for leaves of this sort is bracts. If you look carefully at pine cone bracts, you can see that they circle the pine cone in spirals.
The pirals overlap, but if you look very carefully, you can see two patterns of spirals.
In one pattern the spirals rise at a steep angle from the bottom to the top of the pine cone. These spirals are so steep that they are almost vertical, up and down.
In the other pattern the overlapping spirals rise gradually, round and round the pine cone. These spirals are so gradual that they are almost horizontal, nearly straight across.
Here's how you can count pine cone spirals:
1. Choose several pine cones so you can compare them.
2. Beware that counting the overlapping rows is not easy. Rotate the pine cone in your hand, and touch each bract so you cna follow the spirals around the pine cone. You can make the count easier by marking the rows with colored markers. Mark the colors directly onto the pine cone.
3. Count the gradual rows of bracts.
4. Count the steep rows of bracts.
5. Write the two numbers together as a proportion. You may be writing 3/5. You may be writing 5/8 or 8/13, or another st of Fibonacci numbers.
When you write the two numbers this way, you show how one part of the pine cone relates to anther. This proportion is part of nature's way of protecting and assuring the survival of the pine cone.
This activity is from "Math Wizardry for Kids" by Margaret Kenda and Phyllis S. Williams.
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