new video tackling the question, "how many countries are there?" In the video he explains how countries are defined and recognized by various international organizations including the UN and the IOC. He also jumps into a brief commentary about the relationship between China and Taiwan. The video is embedded below.
After watching How Many Countries Are There? you might want to have students watch CGPGrey's explanation of borders and landlocked countries.
Finally, have your students explore some historical maps to see how borders and country names have changed throughout history.