Answer:
He needs to count three steps to the left-hand-side of -8 to obtain -11
Explanation:
On the number line, 8 is found on right-hand-side of 0, the positive part, and -8 is found on the left-hand-side of 0, the negative part.
To evaluate -8 - 3 on the number line, we use any of the negative part. It looks like this:
...|......|......|......|......|......|......|......|......|......|
-9....-8...-7...-6...-5...-4...-3...-2....-1......0
Since he has found -8 already, all he needs to do is count three steps to the left of -8, to obtain -11.