Since the interval is 1/5 between mixed numbers and since -6 is greater that -7, this means that you will subtracting 1/5 starting from the -6 until you reach the -7.
This can be illustrated as follows:
-6
-6 - 1/5 = -6 1/5
-6 1/5 - 1/5 = -6 2/5
-6 2/5 - 1/5 = -6 3/5
-6 3/5 - 1/5 = -6 4/5
-6 4/5 - 1/5 = -6 5/5 = -7
