Positive numbers are numbers larger than 0. For example, 7 and 10 are positive.
Negative numbers are smaller than zero. Examples include -55 and -81.
Zero falls right in the middle of these two sets of numbers. It's neither positive nor negative. If it was positive, then it would be larger than 0. But a number cannot be larger than itself. Therefore, it can't be positive. We rule out it being negative for similar reasoning.
