well, first find the distance between the two numbers.
This can be done by adding the absolute values.
|12| + |-2| = 14.
mid = half
so what is half of 14? 7 is half of 14.
So, it is 7 less than the last point and 7 more than the first
-2 + 7 = 5
12 - 7 = 5
so, the midpoint is 5.
Hope this helps!