Chapter 1 - Section 1.2 - Algebraic Expressions and Sets of Numbers - Exercise Set - Page 16: 58

8

The absolute value is the number of units a number $x$ is away from 0, and is indicated by putting $x$ between two vertical lines (e.g. |$x$|). Since 8 is 8 units away from 0, the absolute value of 8—written as |8|—is 8.