Question

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

Explanation:

Step1: Identify coordinates

The coordinate of point S is 3 and of point T is 5.

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, $|5 - 3|$.
$|5 - 3|=2$

Answer:

2