Students can check their estimates for the total population of beans in their bags using several methods. For example, they can measure the volume or capacity of all the beans in the bag. If one pound of beans is about 10 of the medium-size scoops used to collect the sample data, they can count the number of beans in one scoop and multiply this number by 10 to estimate the total number of beans in the whole bag.
You can vary the size of the bat caves by giving some groups 2 pounds of beans in their bags. These groups should follow the same procedure. During class discussion, you can compare the two experiments by comparing the graphs, the ratios, and the estimates for the total number of beans in the bags.
Learn more about bats from the Bats Conservation International website, www.batcon.org.
