<P> Imperial units are still used in ordinary conversation . Today, Canadians typically use a mix of metric and imperial measurements in their daily lives . However, the use of the metric and imperial systems varies by age . The older generation mostly uses the imperial system, while the younger generation more often uses the metric system . Newborns are measured in SI at hospitals, but the birth weight and length is also announced to family and friends in imperial units . Drivers' licences use SI units . In livestock auction markets, cattle are sold in dollars per hundredweight (short), whereas hogs are sold in dollars per hundred kilograms . Imperial units still dominate in recipes, construction, house renovation and gardening . Land is now surveyed and registered in metric units, although initial surveys used imperial units . For example, partitioning of farm land on the prairies in the late 19th and early 20th centuries was done in imperial units; this accounts for imperial units of distance and area retaining wide use in the Prairie Provinces . The size of most apartments, condominiums and houses continues to be described in square feet rather than square metres, and carpet or flooring tile is purchased by the square foot . Motor - vehicle fuel consumption is reported in both litres per 100 km and statute miles per imperial gallon, leading to the erroneous impression that Canadian vehicles are 20% more fuel - efficient than their apparently identical American counterparts for which fuel economy is reported in statute miles per US gallon (neither country specifies which gallon is used). Canadian railways maintain exclusive use of imperial measurements to describe train length (feet), train height (feet), capacity (tons), speed (mph), and trackage (miles). </P> <P> Imperial units also retain common use in firearms and ammunition . Imperial measures are still used in the description of cartridge types, even when the cartridge is of relatively recent invention (e.g., . 204 Ruger, . 17 HMR, where the calibre is expressed in decimal fractions of an inch). However, ammunition that is already classified in metric is still kept metric (e.g., 9 × 19mm). In the manufacture of ammunition, bullet and powder weights are expressed in terms of grains for both metric and imperial cartridges . </P> <P> As in most of the western world, air navigation is based on nautical units, e.g., the nautical mile, which is neither imperial nor metric, though altitude is still measured in imperial feet in keeping with the international standard . </P> <P> Metrication in Australia has largely ended the use of imperial units, though for particular measurements (such as flight altitudes and nominal sizes of computer and television screens) international use of imperial units is still followed . In licensed venues, draught beer and cider is sold in glasses and jugs with sizes based on the imperial fluid ounce though rounded to the nearest 5 mL . </P>

Where did imperial units of measurement come from