Answer=A number line from negative 10 to 10 is shown, with numbers labeled at intervals of 2
Remember that subtracting a negative number is the same as adding a positive number, so...
-6-(-8)=-6+8
-6+8=2
Since the answer, 2, and the addends, -6 and 8 fall in between -10 and 10. The number line will suit the problem. They are also all even numbers so if the labels are in intervals of 2, it will be easily read.