A measurement system is a set of units which can be used to specify anything which can be measured. There are various measurement systems used across the world. The system used in the United States is the U.S. customary system. Here are the common units used in this system along with examples to give you a frame of reference.
Inch (in): The distance between the knuckles on your index finger is approximately one inch.
Foot (ft): One foot equals 12 inches. An official professional football is about one foot long.
Yard (yd): One yard equals three feet. A baseball bat is about one yard long.
Mile (mi): One mile equals 5,280 feet. A mile is approximately the distance a championship distance runner can run in just under four minutes.
Ounce (oz): A slice of bread usually weighs a little less than one ounce.
Pound (lb): One pound equals 16 ounces. A loaf of white bread usually weighs a little more than one pound.
Ton (T): A ton is 2,000 pounds. The famous Liberty Bell in Philadelphia weighs about one ton.
Cup (c): A standard baby bottle holds about one cup of juice.
Pint (pt): One pint equals two cups. A pint of ice cream is just about right for four people to share.
Quart (qt): One quart equals two pints. Motor oil typically comes in a quart-sized container.
Gallon (gal): One gallon equals four quarts. A large container of milk contains one gallon.
Knowing these measurement units will help you in school and in everyday life.