For a positive number, it is just the number.
For a negative number it is it's positive value.
So, the absolute value of 5 is 5, and the absolute value of -5 is 5 also.
Absolute value is written like this:  | - 5 | = 5 with vertical bars around the number.
You can think of absolute value as the distance from zero to your number.
Now, here's a problem for you:
What is | - 8 |?