Standing in front of the cashier in the take-out line, you tell them your name so you can pick up that pizza you called in 20 minutes ago. The confused cashier tells you, “Hmm, I don’t have an order ...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com. Who created ...