The burning questions is “Why does it matter”. If you ask an architect, he or she will tell you that an architect scale ruler is vital to their daily business. They would not be able to function without these rulers.
What is an architect scale ruler? It is a special ruler that is marked in special scales that correspond to the scale of the drawing. If the drawing is done in 1″ = 1 foot, then each inch on the correct scale will represent one foot in the drawing. If the drawing is done in 1/4″ = 1 foot, then each quarter inch on the 1/4 scale corresponds to 1 foot in the drawing. On this particular scale, each 1/4 inch is marked 1,2,3,4,5,6 etc. So that the “4 marking number” is one inch from the zero mark. Simple, so far. But each of these rulers has several scales, so you don’t have to have multiple rulers in your pocket. Other scales can be 1/8, 1/16, 1/3, 3/16 and so forth. The trick of this business is to be able to choose the correct scale for each drawing you are working on. If you are reading a highway map which is drawn to 1/4″ = 1 mile, you would use the 1/4 scale. If you are with me up to this point, you could become an architect!