Oh! And another trick to get 1 mistake less.
If revision says: "FLIGHT LEVEL: EIGTH ZERO" you must not type 0-8-0 (as one should expect), but only 8-0.
Test will tell you u've made a mistake.
Different people from different days got same revision error with "8-0", that's why I think exams are exactly repetitions of same pattern.
I asked one of the exam supervisor about this software bug and he said "yes, but we cannot tell anyone because all contestants should face tests under same conditions".