Remember that 1/10th of an hour is 6 minutes and you'll generally find that the speed/times/distance calculations run in multiples of 3 minutes. I.e. The aircraft is doing 450kts how far will it fly in 24 minutes.....
So 450kts G/S is 45nm in 6 minutes, 22.5mn in 3 minutes 180nm in 24 minutes etc.
Makes the mental maths easier to calculate, at least it does in my addled old brain.