# Population Simulation

In science class, you have learned that populations grow—but not without limits. In this activity, you and your family members will create a model fish population and simulate how that population grows and decays over time.

## Materials

• paper cup
• 30 to 40 pennies

## Procedure

Place two pennies (fish) in the cup (pond). Record that number for year 0 in the Population Growth chart. Pour the pennies on a table. For each penny that shows “Heads,” add another fish to the “pond.” Record the fish population for year 1. Put the pennies back in the cup, and repeat for year 2. Continue for up to 8 years or until your run out of pennies. Now you are going to simulate population decay. Count the total number of pennies (fish) you have in all, and put them in the cup. Record that number for year 0. Pour the pennies on the table. A penny that shows “Heads” is a fish that died or was caught. Figure out how many fish are left, and record that population for year 1. Place the “live fish” back in the cup, and repeat for year 2. Continue for up to 8 years.

Population Growth
Year 0 1 2 3 4 5 6 7 8
Number of Fish
Population Decay
Year 0 1 2 3 4 5 6 7 8
Number of Fish

## Results

Did you notice any patterns in the growth and decay of the fish population? If you started with more pennies, do you think you would see the same patterns? How long did it take the population to grow to twice its original size? How long did it take the population to become half its original size?