In a number line, the distance from the point representing a number to the origin is called the absolute value of that number. The absolute value is represented by "||". In a number line, let's assume a > b, and a > 0, b > 0. The value representing the distance between the point representing the number a and the point representing the number b is read as the absolute value of a minus b, denoted as |a-b|.

For example, |5| represents the distance between the point representing the number 5 and the origin on the number line. This distance is 5, so the absolute value of 5 is 5. Similarly, |-5| represents the distance between the point representing the number -5 and the origin on the number line. This distance is also 5, so the absolute value of -5 is 5.

The absolute value of a non-negative number (positive number or zero) is the number itself, and the absolute value of a non-positive number (negative number or zero) is its opposite.

The absolute value of a is represented as "|a|". It is read as "the absolute value of a".

The absolute value of a real number a is always a non-negative number, which means |a| ≥ 0.

The absolute values of two numbers that are opposite to each other are equal, i.e., |-a|=|a| (because their distances from the origin on the number line are equal).

If a is a positive number, then the equation |x|=a has two values for x: ±a. For example, if |x|=3, then x=±3.