You are correct -- in your example (10-6) the first number is the prop diameter in inches, the second number is the pitch number in inches. Pitch refers to the forward distance theoretically travelled by the prop for one revolution. Pitch, however is not necessarilly a real number -- it is affected by errors in the stated pitch number, the efficiency of the prop, the type of aircraft it is fitted to, plus numerous other things. It is, however, a usefull rough guide.