1. Cicada Project
By: Zeba, Sahana,
Patrick

2. Introduction
This is a project about cicadas. Cicadas are very special
animals that are very good mathematicians. It just so
happens as well that cicadas get out of the ground exactly 13
or 17 years after they were born. Is this just a coincidence?
The most logical reason that they come out exactly 13 or 17
years could be because they don’t want to be eaten by their
predators. The table in the next slide explains their predators
and when they attack the cicadas first. The predator A feeds
every two years, the predator B feeds every three years and
finally the predator C feeds every four years.

4. #1: For which cycle lengths will it be at least 100 years before the
cicadas are attacked by all three predators again? What do you
notice about these numbers?
We noticed that all of these numbers are prime numbers. The numbers are
11, 13, and 17.
#2: Explain why you think this happens.
Hint: In the table you completed in 1, look at what
happens when the cycle length has lots of divisors, like 12
years. Why do you think the cicadas get attacked so often
in this case?
This happens because it depends on the amount of factors that the number of
years that the cicadas take to get out of the ground. If it is prime number and
only has two factors then it obviously won’t get attacked by their predators as
often. If it has more factors like the number sixty it will get attacked a lot
more.