Question

what is the length of $overline{ef}$?

Explanation:

Step1: Identify coordinates

The coordinate of point E is 0 and the coordinate of point F is 3.

Step2: Calculate distance

The distance between two points on a number - line is given by the absolute value of the difference of their coordinates. So, \(EF=\vert3 - 0\vert\).
\(EF = 3\)

Answer:

3