A unit is standard quantity used for measuring. In our everyday life we measure in English units. In science, most measurements are taken in metric units. The metric system uses base units such as the meter (m), liter (l) and the gram (g) for each type of measurement, distance, volume and mass. There are times when the size of the unit is not practical for a purpose. It is impractical to measure my weight in grams. The metric system uses prefixes to create new units. The prefixes are based on powers of ten. Three common prefixes are
|
prefix |
value |
example |
example in words |
|
centi- or ‘c’ |
10-2 or 1/100 |
|
100 centimeters equals one meter |
|
milli or ‘m’ |
10-3 or 1/1000 |
|
1000 milliliters equals one liter |
|
kilo or ‘k’ |
1000 |
1 kg = 1000g |
1 kilogram equals 1000 grams. |
