Arithmetic : Real Numbers

Number Line

Real numbers can be represented geometrically on a number line, which is considered to extend indefinitely in both directions.
To make a number line, mark a point on the line as 0 (zero). Then, mark points at convenient regular intervals to the right of 0 as 1, 2, 3, 4, ... and to the left of 0 as −1, −2, −3, −4, ...
The point midway between 1 and 2 is 1.5, and the point midway between 1.5 and 2 is 1.75.
In this way, any real number can be represented by a point on the number line, and any point on the number line can be represented by a real number.

For any two real numbers n and m, three possibilities exist:

• n < m (n is less than m)
  Point representing n lies to the left of point representing m.
• n = m (n equals m)
  Point representing n coincides with point representing m.
• n > m (n is greater than m)
  Point representing n lies to the right of point representing m.