Yardsticks are so named because they are one yard long. One yard is equal to three feet. Essentially, a yardstick is the same as three rulers laid end-to-end. Yardsticks come in handy when you need to measure something that is longer than a foot, such as the width of a cabinet, the height of your toddler or the size of your television screen. The markings on a yardstick can be quite small, so people have to read them very carefully when making precise measurements.
Examine the yardstick. There are numbers on both sides of the stick. The numbers that are further apart measure inches, while the numbers that are closer together measure centimetres.
Look at the centimetre side. There are ten shorter lines between the numbers. These are millimetres. You will occasionally need this side in order to measure very small things that are measured in millimetres or centimetres. Millimetres and centimetres are not used often in the United States, as they are part of the metric system, which has not been formally adopted.
Look at the side with the inches. There are shorter lines between these numbers as well. These lines represent fractional parts of the inch. Usually, the lines that represent ¼ inch, ½ inch and ¾ inch will be slightly longer than the lines between, which represent inches broken up into even more precise fractional parts, such as 3/8 and 5/16. There should be 16 lines for each inch on your yardstick.
Measure the item you want to know the length of, and hold your fingernail at the point on the yardstick where the object ended. Make sure you are using the inch side of the yardstick unless you need to measure something in millimetres or centimetres.
Look at the point on the yardstick that you are holding. Determine exactly what line it is on. The lines between these numbers represent the following fractions: 1/16, 1/8, 3/16, 1/4, 5/16, 3/8, 7/16, 1/2, 9/16, 5/8, 11/16, 3/4, 13/16, 7/8 and 15/16. Round up the number to the nearest quarter fraction unless you are measuring something that must be very exact.
Not every yardstick has sixteen small lines between the numbers. Some have only eight, which measures items to the nearest 1/8 inch.