#### Answer

A number line is a horizontal line with numbers plotted at various intervals with dots and/or tick marks.

#### Work Step by Step

A number line is a horizontal line with numbers plotted at various intervals with dots and/or tick marks. The numbers increase from left to right and therefore the number line can be used to visually represent the "location" of a number and to show how it relates to other nearby numbers. For example, see the plot of the number $1/4=0.25$ on a number line.