|≈||approximately equal to|
|digits||indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …)|
An attometer is a unit of length, a combination of the metric prefix atto (symbol a) and the SI unit of length meter (symbol m), equal to 10−18 meter or 1.0E-18 meter and its symbol is am. Plural name is attometers.
A metric mile is a distance which approximates one statute mile (1609.344 m) at a round figure of metres (the SI or metric unit of length). The term is most commonly used in track running and swimming.
In track running, the 1500 m race became the standard middle distance race in Europe in the late 19th century, and has been the standard distance in the Olympic Games since 1896. The distance of the race is sometimes referred to as a metric mile.