Absolute value
The absolute value of a number is its distance from zero without considering which direction from zero the number lies. We denote it with ||. E.g. the absolute value of 5 is 5 (|5|=5), and the absolute value of −5 is also 5 (|−5|=5). As you can see, the absolute value of a number is never negative.
When doing calculations with absolute value, you should respect order of operations and evaluate it at first as parentheses, e.g:
$$−5+7×|3−8|=$$
$$=−5+7×|−5|=$$
$$=−5+7×5=−5+35=30$$
