ヤード・ポンド法
Metrication in the United Kingdom, the process of introducing the metric system of measurement in place of imperial units, has made steady progress since the mid–20th century but today remains equivocal and varies by context. Most of government, industry and commerce use metric units, but imperial units are officially used to specify journey distances, vehicle speeds and the sizes of returnable milk containers, beer and cider glasses (though fresh milk is often still sold in multiples of pints, with the metric equivalent also marked). Imperial units are also often used to describe body measurements and vehicle fuel economy. In schools metric units are taught and used as the norm. Imperial units that remain in common usage in the UK are also taught.