Sometimes the reality is easier if you read the words.
( Minus 80 is divided by Minus 10 ,,,,, 8 times ).
Minus 80
-------------- = minus70 ,,,,,,,,1 time
Minus 10
Minus 70
-------------- = Minus 60 ,,,,,,, 2 times
Minus 10
and so on until ten cycles have been completed, you end up with eight the number of times that -80 can be divided by-10.