Hiya,
You check your speed, check on the nomo, you see your speed against a time/distance
Easiest way to imagine it is like a car
You're doing 60mph, in 60mins you will of covered 60 miles, so at 30mins time you will have done 30mins, 15mins only 15miles
Eg : you need to get ahead of a convoy, you have a good idea which area you need to intercept, use your nomo to see time/distance at your speed to get ahead and lay in wait, this depends on how accurate you are at figuring their speed
Not got a printout of nomo, but you can half say 14knts to get 7knts etc if it makes it easier to figure things out
But all a nomo does is show at a set speed how far in distance and time taken you will have gone
