Ida puts her coffee into the microwave, as she does every morning, for exactly two minutes. When the microwave goes off, she opens the door, but then closes the door again and sets the microwave for two more seconds. What good would two more seconds be?
A group of ten people are going out for pizza but only two of them have an umbrella to keep them dry. Somehow they are able to walk all the way to the pizza place without getting wet. How?
Zero is nothing, yet when you add zeroes to a number like 1, it becomes 10, 100 or 1,000.
The ancient Greeks did not have a name for zero and did not use a placeholder. They seemed unsure about the status of zero as a number, philosophizing about how nothing could be something. Once zero was added, it allowed for more mathematical understanding.