OvERVIEW O A measurement is the size amount or degree of an item Many things can be measured including length area volume angles weight temperature and time an Iran and I a to a 0 0 0 0 0 0 0 0 0 ft Using a protractor a carpenter is measuring an angle so that he knows where to cut the board Precise measurements are important in construction and many other
Different measurements require different tools For example to measure the length of a piece of wood you could use a ruler But to measure temperature you would use a thermometer Different units are used too Length can be measured in meters in the metric system or feet in the English system There are also Smaller and larger units The important thing is that each unit A thermometer always represents the same measures temperature standard As you can see this a thermometer is measuring A unit is a definite something very cold How NA quantity used as a many degrees below zero standard of measurement is it
STANDARD MEASUREMENTS In order to be accurate all measurements must make a comparison with something called a standard A standard is an amount upon which everyone agrees Units are the ames for different standards For example one unit for weight is the gram Everyone agrees that 1 gram is a certain amount of weight Two grams equal twice that amount and so on Some standards are based on fundamental laws of nature For instance the meter is defined as the distance traveled by One gram means the same thing everywhere That way When people bake cakes they always use the right amount of I sugar I2 D
light in a vacuum during a period of 1299 792 458th of a second Other standards are physical items For example the kilogram is measured as being equal to the mass of an actual metal cylinder This cylinder is housed in France and is known as the international prototype kilogram THINK ABOUT IT What if there were no standard measurements If you and somebody else both measured the length of a room with your feet for instance what problem might arise The original kilogram standard is kept under glass at the International Bureau of Weights and Measures in France It is made of platinum and iridium O
