In this lesson, students use a base number (1,000, 100, or 20) to compare the numbers of extinct, endangered, and vulnerable species and consider how their actions can help protect animals and plants.

Inquire: Students estimate the number of living things in a group to get a sense of the large number of species in the world.

Investigate: Students write numbers to represent the number of living things on the IUCN's Red List.

Inspire: Students compare and contrast numbers to compare groups of living things, reflecting on how to help living things in their community.