PilotChick,
If it helps, I have to think of the one in sixty in terms of dumper-trucks (don't ask why...). I know that if I go sixty dumper trucks along, and one to the side, I've made a degree. From that I can work backwards for lesser distances. 15 dumper trucks along and already one sideways? Must be 4 degrees!
I'm now a navigator on Tornado GR4....
Draw your own conclusion!
Blunty