1. Observing Populations Cacn Birb Andc

2. Direct observation is counting each member in a population. Ex: We went to a fish tank and counted all of the fish in the tank.

3. Indirect Observation Indirect observation is observing signs of organisms such as nests or burrows and estimating how many organisms live in each one. Ex: We went to the classroom and counted each chair to determine how many students there are.

4. Sampling Sampling is counting an area and then multiplying. Ex: We went to a forest and counted 10 yards of trees and multiplied it by ten because there was 100 yards of forest.

5. Mark And Recapture Mark and recapture: catch an organism, mark it in a way and release it. Recapture and return. Count the ones marked and unmarked. Ex: we went to the bay caught turtles, marked them and then released them. We came back later and captured them again. We then counted the ones marked and unmarked. Then we estimated the amount of turtles in the bay.