The absolute value is to write the nubmer as a positive number
For example:
|-4| = 4
|-2.5| = 2.5
| 6| = 6
So, the number if was negative, we will make it positive
And the number if positive, will remain as it is
There is no need to use the number lines
So, the absolute value of 5.23 = | 5.23 | = 5.23