Number line
In mathematics education, the term "number line" refers to the visualization of the real numbers as points on a straight line.
In the picture, the locations of the points of the integers have been highlighted by vertical lines.
The number line is an illustration of the one-dimensional Euclidean vector space 
. The illustration makes it clear that the set of real numbers forms a linear order by means of the usual comparisons. The number line continues in both directions to infinity. The arrow on the right side of the diagram indicates that the numbers increase in this direction.
In class, a number line is used to illustrate the natural numbers.
The figure below shows the location of some special real numbers: the square root of 2, Euler's number 
and the circle number π 
.
Relationship between point and vector on the number line.
See also
- Number circle
- Gaussian number plane
- Construction with compass and ruler
