Measuring Up

     When you measure, you make observations involving numbers and units. Most people use the International System (SI) units in daily life. Scientists around the world use the SI, or metric system.

     The metric system is based on multiples of 10. In the metric system units are divided into smaller units using prefixes such as milli-, centi- and deci-. Base units are changed to bigger units using prefixes such as deca- and kilo-. 

• Measuring length

Length is the distance between two points. The base metric unit for length is  meter. Rulers, metersticks and tape measures are tools used to measure lenght. 

           
                   

         

                                   

• Measuring time

Time describes how long events take. The base unit of time is the second. Larger units are the minute, the hour and the day. Smaller units include the millisecond and microsecond. Clocks, stopwatches, timers and calenders are some of the tools used to measure time. 

• Measuring temperature

Temperature describes how hot or cold something is. Thermometers are used to measure temperature. Scientists measure temperature in degrees Celsius. so do most other people around the world. In the United States, degrees Fahrenheit are used to report the weather, to measure body temperatures and in cooking.