¿Cómo leer una regla de escala 1/2?

The text describes how to read specific reductions on a standard triangular architect's scale. On an architect's scale, the primary units (whole numbers) represent feet, while the subdivided section at the zero-end breaks those feet down into inches and fractions of an inch to make drawing and measuring blueprints proportional.

For example, in the 1/21/21/2 scale (1/2′′=1′−0′′1/2^{\prime\prime} = 1^{\prime}-0^{\prime\prime}1/2′′=1′−0′′), each main foot division represents one foot in reality, and the finer subdivisions allow you to measure down to precise fractions of an inch. Similarly, the 3/43/43/4 scale (3/4′′=1′−0′′3/4^{\prime\prime} = 1^{\prime}-0^{\prime\prime}3/4′′=1′−0′′) provides a larger, more detailed representation used for floor plans and elevations.