Answer: 8 units
Step-by-step explanation: In this problem, the given numbers -8 and -16 represent the coordinates of the endpoints of a segment and we are asked to find the length of the segment.
To find the length of a segment, we take the greater endpoint coordinate minus the lesser endpoint coordinate.
In this case, the greater endpoint coordinate is -8 and the lesser endpoint coordinate is -16.
So, we have -8 - (-16) which can be thought of as -8 + 16 which equals 8.
Therefore, the length of this segment is 8 units.