Click the link. Watch the Mystery Science video with a friend, "How old is the Earth?" Find the three dots on the bottom. Find the box that says, Edit People, Folders, Date. Tap that box. Then tap Edit People to find your friend's name. Check their name to add to this activity. use the draw tool to circle the ways scientist use to find out how old the Earth is use the label tool to record how old the scientists think the Earth is? You might have to go and look again at the video.