Examine your standard, 1/16-inch English ruler. Notice the different parts, specifically the numerals and the dash marks on the ruler.
Count the numerals on the ruler. You should count 12 or 14 numerals. Each number represents a whole inch mark.
Count the vertical dashes in between two of the numerals. You should count 15 dashes. Each of these dashes represents 1/16 of an inch.
Place an object to be measured, such as a crayon or sharpened pencil, on your work space. Place the ruler directly beneath the object.
Write down the last numeral on the ruler without surpassing the length of the object. For example, if your crayon's length stretches between the third and fourth inch mark but does not quite reach the fourth inch mark, write down "3."
Count the number of vertical dashes from that last numeral all the way to the end of the object. Each of these dashes represents 1/16 of an inch. Write down that number as a fraction. For example, if you count four dashes, write down "4/16."
Reduce your fraction, if possible. For example, 4/16 reduces to ¼. Add the inch number and the fraction number together. In this example, your final measurement would be 3 1/4 inches.