Declaration of net quantity in terms of yards, feet, and inches shall be expressed as follows:

(a) If less than 1 foot, in terms of inches and fractions thereof.

(b) If 1 foot or more, in terms of the largest whole unit (a yard or foot) with any remainder in terms of inches or common or decimal fractions of the foot or yard, except that it shall be optional to express the length in the preceding manner followed by a statement of the length in terms of inches.