On a number line, what is the point labeled 0 called?

1. A number line has equally spaced points labeled with numbers. 2. The starting point of the number line is labeled 0. 3. The point labeled 0 is called the origin. 4. The coordinate is the number paired with a point, the denominator belongs to fractions, and the remainder belongs to division, so none of those name the point 0. _Source: OpenStax Prealgebra (CC BY 4.0), Ch 1 "Whole Numbers", section 1.1 Introduction to Whole Numbers_