With a discussion and a brief film, introduce populations. Using paper fish models, your class participates in a simulation in which they survey numbers of fish. As a class, they tally up the different types. The challenge with this activity is finding the time to cut out a myriad of paper fish. Perhaps a more time-effective way to carry out this population study would be to use a bucket of plastic toy animals or blocks, different-shaped pasta noodles, or construction paper circles (easier to cut out than fish). Count yourself lucky if you have a fish die-cut that you can use!