1.2 COMMON LANGUAGE 8 SYSTEMS OF MEASUREMENT When this system was established, by the Weights and Measures Act in 1824, Britain was an Empire. The system of measuring units commonly used in the world is the SI (Sist me International d Unit s (International System of Units), or metric system. This system was adopted for the first time in France at the end of The imperial system is still the 18th century and spread over Europe the main measuring system first, and outside Europe later, but not in in countries such as Liberia and Myanmar, which were the British Isles. In Britain, a different former British colonies. measuring system, called the imperial system was employed; this system was then established Steps to Length Conversion as the official one in 1824. Although the SI was finally introduced in Kilo Britain in 1965, the Hecto imperial is still the most Deka commonly Base unit used system of measurement Deci in that Centi country and in Milli a few other countries in the world. The names of the metric units are formed by adding a prefix to the basic units of measurement. Prefixes generally come from ancient Greek or Latin numbers. The abbreviation lb derives from the Latin word libra, which was a Roman unit for measuring weight, divided in 12 ounces (called uncias). ONLINE RESOURCES Ancient measuring systems slight: leggero 28 COMMON GROUND The United States of America use the socalled United States Customary system , which is very similar to the imperial system, from which it is derived. Differences between the systems The metric system is based on multiples of ten. This means that each successive unit is ten times larger than the previous one. For example, having a metre as a base unit, a decimetre is ten times smaller; so, one metre equals ten decimetres; a dekametre, instead, is ten times larger, so it is formed by ten metres . The imperial system, on the contrary, has no specific pattern in the conversion from one unit to the other; for example, there are twelve inches in one foot, but there are three feet in one yard. Here is a table of the most common imperial units and their correspondence to the SI ones. The US Customary system employs the same units as the imperial system; however, there are slight differences in the equivalence with the metric system as far as volume units are concerned. Quantity Unit Corresponds to Equals Length 1 inch (in, also indicated with ) 1 foot (ft, also indicated with ) 1 yard (yd) 1 mile (m) 12 inches 3 feet/36 inches 1,760 yards 2.54 centimetres 30.48 centimetres 91.44 centimetres 1.609 kilometres Volume (British values) 1 fluid ounce (fl oz) 1 pint (pt) 1 quart (qt) 1 gallon (gal) 20 fluid ounces 2 pints 4 quarts 28.41 millilitres 568.26 millilitres 1.137 litres 4.546 litres Volume 1 fluid ounce (fl oz) (American 1 pint (pt) 1 quart (qt) values) 1 gallon (gal) 16 fluid ounces 2 pints 4 quarts 29.57 millilitres 473.17 millilitres 0.946 litres 3.785 litres Weight 16 ounces 2,240 pounds 28.34 grams 453.5 grams 1,016 kilograms 1 ounce (oz) 1 pound (lb) 1 ton