<P> The metric system features a single base unit for many physical quantities . Other quantities are derived from the standard SI units . Multiples and fractions are expressed as powers of 10 of each unit . When smaller or larger units are more convenient for given use , metric prefixes can be added to the base unit to denote its multiple by a power of ten : a thousandth ( 10 ) of a metre is a millimetre , while a thousand ( 10 ) metres is a kilometre . Unit conversions are thus always simple , so that convenient magnitudes for measurements are achieved by simply moving the decimal place : 1.234 metres is 1234 millimetres or 0.001234 kilometres . The use of fractions , such as 2 / 5 of a metre , is not prohibited , but uncommon . There is no profusion of different units with different conversion factors as in the Imperial system which uses , for example , inches , feet , yards , fathoms , and rods for length . </P>
<P> The metric system features a single base unit for many physical quantities . Other quantities are derived from the standard SI units . Multiples and fractions are expressed as powers of 10 of each unit . When smaller or larger units are more convenient for given use , metric prefixes can be added to the base unit to denote its multiple by a power of ten : a thousandth ( 10 ) of a metre is a millimetre , while a thousand ( 10 ) metres is a kilometre . Unit conversions are thus always simple , so that convenient magnitudes for measurements are achieved by simply moving the decimal place : 1.234 metres is 1234 millimetres or 0.001234 kilometres . The use of fractions , such as 2 / 5 of a metre , is not prohibited , but uncommon . There is no profusion of different units with different conversion factors as in the Imperial system which uses , for example , inches , feet , yards , fathoms , and rods for length . </P>
a reference point from which all other measurements are made is called a ( n )
a reference point from which all other measurements are made is called a ( n )
base unit
base unit