A yardstick measures one yard -- 36 inches. Marks located along the sides of a yardstick represent fractions of an inch. Each fractional measurement has a specific line length. The length of the marked lines varies depending on the size of the fraction. Learning to distinguish the types of lines and their location on the yardstick will allow you to perform precise measurements.
Set a yardstick on a flat surface.
Note the evenly spaced lines of varying length sitting between the numbers printed on the ruler's face. Each line length represents a fraction of an inch. The longest lines — centered between two numbers — equals a 1/2 inch. The second longest lines represent a 1/4 inch. Between the 1/4-inch lines, sit the shorter 1/8-inch lines. The shortest line on the yard rule represent a 1/16 inch.
Align the zero end of the yard stick with an object.
Note the length of the line sitting even with the object's opposite edge. Count backward from the line to the nearest whole number sitting over the object. For example, if the longest line past the number 14 aligns with the end of the object, the object is 14 1/2 inches long.