Population Education has a free resource center that is filled with lessons and activities for all grade levels. All lessons and activities center around population issues, human-environment interaction, and global interaction. The topics cover all curricular areas. The lessons are grouped by grade level and are linked to the common core curriculum.
(This image is from a math lesson on world population)
The lessons are interactive and include the student work pages so they are ready for use by your students.
This lesson on the water system and drinking water supply is hands-on and gives a good understanding on how little water in the world is drinkable.
Click on the pictures to go to the respective page or lesson to learn more and explore this resource!