Decimalisation is the conversion of a measurement system to units related by powers of 10, replacing traditional units that are related in other ways, such as those formed by successive doubling or halving, or by more arbitrary conversion factors. Units of physical measurement, such as length and mass, were decimalised with the introduction of the metric system, which has been adopted by almost all countries with the prominent exception of the United States. Thus a kilometre is 1000 metres, while a mile is 1,760 yards. Electrical units are decimalised worldwide. Common units of time remain undecimalised; although an attempt was made during the French revolution, this proved to be unsuccessful and was quickly abandoned.

While metrication describes the adoption by different countries of a common system of decimalised metric measurements, countries generally have their own currencies. The decimalisation of currencies is the process of converting each country's currency from its previous non-decimal denominations to a decimal system, with one basic unit of currency and one or more sub-units, such that the number of sub-units in one basic unit is a power of 10, most commonly 100). The decimalisation process for individual countries is described below.

The only current non-decimal currencies are the Malagasy ariary (equal to five iraimbilanja) and the Mauritanian ouguiya (equal to five khoums), though in practice both just have one currency unit and no sub-unit because khoums and iraimbilanja are no longer minted.

Decimal measurements

The idea of measurement and currency systems where units are related by factors of ten was suggested by Simon Stevin who in 1585 first advocated the use of decimal numbers for everyday purposes.[1] The Metric System was developed in France in the 1790s as part of the reforms introduced during the French Revolution. Its adoption was gradual, both within France and in other countries, but its use is nearly universal today. One aspect of measurement decimalisation was the introduction of metric prefixes to derive bigger and smaller sizes from base unit names. Examples include kilo for 1000, hecto for 100, centi for 1/100 and milli for 1/1000. The list of metric prefixes has expanded in modern times to encompass a wider range of measurements.

While the common units of time, minute, hour, day, month and year, are not decimalised, there have been proposals for decimalisation of the time of day and decimal calendar systems. Astronomers use a decimalised Julian day number to record and predict events.

Decimal currency

Decimal currencies have sub-units based on a factor of 10. There are most commonly 100 sub-units to the base currency unit, but currencies based on 1,000 sub-units also exist, especially in Arab countries. The Chinese Yuan is widely considered to be the first decimal currency.[2]

For example:

Historically, non-decimal currencies were much more common: such as the British pound sterling before decimalisation in 1971. Until 1971, the pound sterling had sub-units of account of shillings (20 to a pound) and pence (12 to a shilling). Like other currencies, it also had coins with other names (ha'pence, guineas, and crowns); and in addition, until 1960 the penny was divided into 4 farthings. There were nineteen different fractions of a pound of a whole number of pence. For example, a third, quarter, fifth and sixth of a pound were respectively 80, 60, 48, and 40 pence, normally written as shillings and pence: 6/8, 5/-, 4/-, and 3/4. There were eight additional fractions which were a whole number of farthings (for example, one sixty-fourth of a pound was three pence three farthings, written ​3 34d).


Russia converted to a decimal currency under Tsar Peter the Great in 1704, with the ruble being equal to 100 kopeks, thus making the Russian ruble the world's first decimal currency.[3]

France introduced the franc in 1795 to replace the livre tournois,[4] abolished during the French Revolution. France introduced decimalisation in a number of countries that it occupied during the Napoleonic period.

Dutch guilder decimalised in 1817 (became equal to 100 centen instead of 20 stuivers = 160 duits = 320 penningen), with last pre-decimal coins withdrawn from circulation in 1848.

Sweden introduced decimal currency in 1855. The currency riksdaler was divided into 100 öre. The riksdaler was renamed krona in 1873.

The Austro-Hungarian Empire decimalised the Austro-Hungarian gulden in 1857, concurrent with its transition from the Conventionsthaler to the Vereinsthaler standard.

Spain introduced its decimal currency unit, the peseta, in 1868, replacing all previous currencies.

Cyprus decimalised the Cypriot pound in 1955, which comprised 1,000 mils, later replaced by 100 cents.

On Decimal Day, 15 February 1971, the United Kingdom decimalised the pound sterling and Ireland decimalised the Irish pound (see below).

Malta decimalised the lira in 1972.

The euro, which comprises 100 cents, was introduced in the eurozone, and as of 2015, it replaced 19 national currencies in Europe.

£sd conversion

In places where £sd was used, the decimalisation process either defined one new penny = ​1100 pound, where the main unit (the pound) was unchanged, or introduced a new main unit (such as the dollar for Australia and New Zealand), equivalent to ten shillings (half a pound), with one cent = ​1100 dollar.

The following table shows the conversion of common denominations of coins of the £sd system.

Common name Amount New £p New $c
Halfpenny 12d. 524p ≈ 0.2083p 512c ≈ 0.4167c
Penny 1d. 512p ≈ 0.4167p 56c ≈ 0.833c
Threepence 3d. 1 14p 2 12c
Sixpence 6d. 2 12p 5c
Shilling 1/- 5p 10c
Florin 2/- 10p 20c
Half crown 2/6 12 12p 25c
Crown 5/- 25p 50c
Half sovereign 10/- 50p $1
Sovereign £1 £1 $2
Two pound coin £2 £2 $4

The farthing, at ​14 penny, was never converted, as it ceased to be legal tender a decade prior to decimalisation. In 1971, a new penny would have been worth 9.6 farthings (making a farthing slightly more than 0.104 new pence).


North America

United States

In 1784, Thomas Jefferson proposed a decimal currency system based on the Spanish dollar, with coins for 10 dollars, 1 dollar, 110 dollar, and 1100 dollar; possibly supplemented by a half-dollar, "double tenth", and "five copper piece". One argument he advanced in favour of this system was that the ​1100-dollar coin would be similar in value to existing copper coins:[5]

States Denomination
Delaware, Maryland, New Jersey, Pennsylvania pound = 2​23 dollar
North Carolina, New York pound = 2​12 dollar
Connecticut, Massachusetts, New Hampshire, Rhode Island pound = 2​29 dollar

The initial currency of the United States was of decimal denomination from the outset of home minted currency in 1792 with the dollar being equal to 100 cents, but other currencies were also accepted for some time afterwards. For example, the Spanish dollar, a non-decimalised currency, was accepted as official currency in the United States alongside the U.S. dollar until 1857.[6]


Decimalisation in Canada was complicated by the different jurisdictions before Confederation in 1867. In 1841, the united Province of Canada's Governor General, Lord Sydenham, argued for establishment of a bank that would issue dollar currency (the Canadian dollar). Francis Hincks, who would become the Province of Canada's Prime Minister in 1851, favoured the plan. Ultimately the provincial assembly rejected the proposal.[7] In June 1851, the Canadian legislature passed a law requiring provincial accounts to be kept decimalised as dollars and cents. The establishment of a central bank was not touched upon in the 1851 legislation. The British government delayed the implementation of the currency change on a technicality, wishing to distinguish the Canadian currency from the United States' currency by referencing the units as "Royals" rather than "Dollars".[8] The British delay was overcome by the Currency Act of 1 August 1854. In 1858, coins denominated in cents and imprinted with "Canada" were issued for the first time.

Decimalisation occurred in:[9]

Date Notes
Province of Canada 1 August 1854
Nova Scotia 1 July 1860 Ordered its first coinage in 1860, but the coins were not shipped by the Royal Mint until 1862
New Brunswick 1 November 1860 Like Nova Scotia, the coins were received in 1862
Newfoundland 1866 Took effect in early 1865 and had different coinage from 1865 to 1947
Vancouver Island 1863
British Columbia 1865
Manitoba 1870
Prince Edward Island 1871

The colonial elite, the main advocates of decimalisation, based their case on two main arguments:[10] The first was for facilitation of trade and economic ties with the United States, the colonies' largest trading partner; the second was to simplify calculations and reduce accounting errors.[11]

Mexico and Bermuda

The Mexican peso was formally decimalised in the 1860s with the introduction of coins denominated in centavos; however, the currency did not fully decimalise in practice immediately and pre-decimal reales were issued until 1897.

Bermuda decimalised in 1970, by introducing the Bermudian dollar equal to 8 shillings 4 pence (100 pence, effectively equal to the US dollar under the Bretton Woods system).


Central America

South America

  • The Venezuelan peso decimalised in 1843.
  • The Colombian peso decimalised in 1847 (became equal to 10 décimos instead of 8 reales, later became equal to 100 centavos).
  • The Chilean peso decimalised in 1851 (became equal to 10 décimos or 100 centavos instead of 8 reales).
  • The Peruvian sol decimalised in 1863 (equal to 10 dineros or 100 centavos).
  • The Paraguayan peso decimalised in 1870 (became equal to 100 centésimos, later centavos, instead of 8 reales).
  • The Ecuadorian peso decimalised in 1871.
  • The Argentine peso decimalised in 1881.


South Africa

The rand was introduced on 14 February 1961. A Decimal Coinage Commission had been set up in 1956 to consider a move away from the denominations of pounds, shillings and pence, submitting its recommendation on 8 August 1958.[12] It replaced the South African pound as legal tender, at the rate of 2 rand = 1 pound or 10 shillings to the rand. Australia, New Zealand and Rhodesia also chose ten shillings as the base unit of their new currency.


Australia and New Zealand

1964 ABC report describing the design of the soon to be introduced Australian decimal coins.

Australia decimalised on 14 February 1966, with the new Australian dollar equivalent to ten shillings or half an Australian pound in the previous currency. Since a shilling became equal to ten cents, the Australian cent was equal to 1.2 Australian pence, although they were usually exchanged on a 1:1 basis during the brief period when both were circulating. A television campaign containing a memorable jingle, sung to the tune of Click Go the Shears, was used to help the public to understand the changes.[13]

New Zealand decimalised on 10 July 1967, with the New Zealand dollar replacing the New Zealand pound. The conversion rates were the same as Australia's—10c to one shilling, one dollar to 10 shillings, and two dollars to one pound. Confusion was expected with twelve pence becoming ten cents, such as people expecting four cents' change from paying ten cents/one shilling for an item costing eight cents. To help avoid this, the Decimal Currency Board recommended on inter-currency transactions (e.g., paying 4c with £sd coins, or paying 4d with decimal coins) to pay to the next highest five cents or sixpence to get the correct change.

Rest of Oceania


Sri Lanka (known as Ceylon at the time) decimalised in 1869.

King Chulalongkorn decimalised the Thai currency in 1897.

India changed from the rupee, anna, pie system to decimal currency on 1 April 1957.

Yemen Arab Republic introduced coinage system of 1 North Yemeni rial=100 fils in 1974, to replace former system of 1 rial = 40 buqsha = 80 halala = 160 zalat. The country was one of the last to convert its coinage.

Japan historically had two decimalisations of the yen, the sen (1/100) and the rin (1/1,000). However, they were taken out of circulation as of December 31, 1953, and all transactions are now conducted in round amounts of 1 yen or greater.[14]

Rupee-anna-paisa-pie conversion

In India, Pakistan, and other places where a system of 1 rupee = 16 annas = 64 paise = 192 pies was used, the decimalisation process defines 1 naya paisa = ​1100 rupee. The following table shows the conversion of common denominations of coins issued in modern India and Pakistan. Bold denotes the actual denomination written on the coins

Rupee Anna Paisa Pie Naya paisa
1192 112 13 1 2548 ≈ 0.5208
1128 18 12 1 12 2532 = 0.78125
164 14 1 3 1 916 = 1.5625
132 12 2 6 3 18 = 3.125
116 1 4 12 6 14 = 6.25
18 2 8 24 12 12 = 12.5
14 4 16 48 25
12 8 32 96 50
1 16 64 192 100

Non-currency cases (security market)

In the special context of quoting the prices of stocks, traded almost always in blocks of 100 or more shares and usually in blocks of many thousands, stock exchanges in the United States used eighths or sixteenths of dollars, until converting to decimals between September 2000 and April 2001.[15]

Similarly, in the UK, the prices of government securities continued to be quoted in multiples of ​132 of a pound (​7 12 d or ​3 18 p) long after the currency was decimalised.

Mauritania and Madagascar

Mauritania and Madagascar theoretically retain currencies with units whose values are in the ratio five to one: the Mauritanian ouguiya (MRO) is equivalent to five khoums, and the Malagasy ariary (MGA) to five iraimbilanja.

In practice, however, the value of each of these two larger units is very small: as of 2010, the MRO is traded against the euro at about 370 to one, and the MGA at about 2,900 to one. In each of these countries, the smaller denomination is no longer used, and coins denominated in khoums and iraimbilanja are no longer minted. Therefore, in practice, they are neither decimal nor non-decimal currencies as there is no sub-unit.

Influence on the introduction of the euro

Before introducing physical euro notes and coins on 1 January 2002, previous decimalisation efforts, particularly that of the UK in 1971, were studied by the European Central Bank.[16] Questions included how to most effectively educate the public (particularly the elderly), the duration of the transition, the likely speed of uptake, the likely effects on inflation for currencies where one euro cent, the smallest circulating denomination, was greater in value than the smallest coin in circulation before the transition, and the likely criminal activities which might be attempted during the transition period.

See also


  1. ^ "Simon Stevin (Dutch mathematician) - Britannica Online Encyclopedia". Retrieved 2018-10-26.
  2. ^ Heefer, Albrecht (24 May 2016). "Welk land voerde als eerste het decimale stelsel voor zijn valuta in" [Which country was the first to introduce a decimal system for its valuta] (in Dutch). Retrieved 8 June 2016.
  3. ^ The new Encyclopaedia. Britannica. Volume 25.1994
  4. ^ Gadoury, V. "Monnaies Françaises" p.48 (1999)
  5. ^ Jefferson, Thomas (1905). "Notes on the Establishment of a Money Unit, and of a Coinage for the United States". In Ford, Paul Leicester. The Works of Thomas Jefferson. 4 (Notes on Virginia II, Correspondence 1782–1786) (Federal ed.). Retrieved 21 January 2014.
  6. ^ "A Century of Lawmaking for a New Nation: U.S. Congressional Documents and Debates, 1774 - 1875".
  7. ^ McCulloch, A. B. “Currency Conversion in British North America, 1760–1900.” Archivaria 16, (Summer 1983): 83-94.
  8. ^ Canadian Mint. “Currency Reforms, 1841 – 71.” A History of the Canadian Dollar. Ottawa: Canadian Mint, 2003.
  9. ^ Canadian Mint. “Currency Reforms, 1841 – 71.” A History of the Canadian Dollar. Ottawa: Canadian Mint, 2003.
  10. ^ Mushin, Jerry. “Twentieth Century Currency Reforms: A Comment.” Kyklos 50 (1997): 247 – 249.
  11. ^ W.T. Easterbrook and Hugh G.J. Aitken, Canadian Economic History (Toronto: University of Toronto Press, 1988), 381.
  12. ^ Mboweni, T.T. 2001. The Reserve Bank and the Rand: some historic reflections. Speech by the Governor of the Reserve Bank 29 Nov 2001.
  13. ^ "Australian Dollar Bill Currency Decimal Jingle from 1965".
  14. ^ "通貨の単位及び貨幣の発行等に関する法律".
  15. ^ "SEC Testimony: Decimal Pricing in the Securities and Options Markets (A. Levitt)".
  16. ^ Moore, N. E. A. (June 1995). "The Introduction of Decimal Currency in the UK in 1971. Comparisons with the Introduction of a Single European Currency" (PDF). European Papers. European Commission Director-General for Economic and Financial Affairs (111). Retrieved 21 January 2014.
Coins of the pound sterling

The standard circulating coinage of the United Kingdom is denominated in pounds sterling (symbol "£"), and, since the introduction of the two-pound coin in 1994 (to celebrate the 300th anniversary of the Bank of England 1694–1994), ranges in value from one penny to two pounds. Since decimalisation, on 15 February 1971, the pound has been divided into 100 (new) pence. From the 16th century until decimalisation, the pound was divided into 20 shillings, each of 12 (old) pence. British coins are minted by the Royal Mint in Llantrisant, Wales. The Royal Mint also commissions the coins' designs.

As of 31 March 2016, there were an estimated 30.14 billion coins circulating in the United Kingdom.The first decimal coins were circulated in 1968. These were the five pence (5p) and ten pence (10p), and had values of one shilling (1/-) and two shillings (2/-), respectively, under the pre-decimal £sd system. The decimal coins are minted in copper-plated steel (previously bronze), nickel-plated steel, cupronickel and nickel-brass. The two-pound coins, and, as from 28 March 2017 the new one-pound coins, are bimetallic. The coins are discs, except for the twenty pence and fifty pence pieces, both of which have faces that are heptagonal curves of constant width, and the new one-pound coins, which have faces with 12 sides. All the circulating coins have an effigy of Queen Elizabeth II on the obverse, and various national and regional designs, and the denomination, on the reverse. The circulating coins, excepting the two-pound coin, were redesigned in 2008, keeping the sizes and compositions unchanged, but introducing reverse designs that each depict a part of the Royal Shield of Arms and form (most of) the whole shield when they are placed together in the appropriate arrangement (see photo). The exception, the 2008 one-pound coin, depicts the entire shield of arms on the reverse. All current coins carry a Latin inscription whose full form is ELIZABETH II DEI GRATIA REGINA FIDEI DEFENSATRIX, meaning "Elizabeth II, by the grace of God, Queen and Defender of the Faith".

In addition to the circulating coinage, the UK also mints commemorative decimal coins (crowns) in the denomination of five pounds. Prior to decimalisation, the denomination of special commemorative coins was five shillings, that is, ​1⁄4 of a pound. Crowns, therefore, had a face value of 25p from decimalisation until 1981, when the last 25p crown was struck. Ceremonial Maundy money and bullion coinage of gold sovereigns, half sovereigns, and gold and silver Britannia coins are also produced.

Some territories outside the United Kingdom, which use the pound sterling, produce their own coinage, with the same denominations and specifications as the UK coinage but with local designs.

In the years just before decimalisation, the circulating British coins were the half crown (2/6, withdrawn 1 January 1970), two shillings or florin (2/-), shilling (1/-), sixpence (6d), threepence (3d), penny (1d) and halfpenny (​1⁄2d). The farthing (​1⁄4d) had been withdrawn in 1960. There was also the Crown (5/-), which was, and still is legal tender, worth 25p, but normally did not circulate.

All modern coins feature a profile of the current monarch's head. The direction in which they face changes with each successive monarch, a pattern that began with the Stuarts. For the Tudors and pre-Restoration Stuarts, both left and right-facing portrait images were minted within the reign of a single monarch. In the Middle Ages, portrait images tended to be full face.

From a very early date, British coins have been inscribed with the name of the ruler of the kingdom in which they were produced, and a longer or shorter title, always in Latin; among the earliest distinctive English coins are the silver pennies of Offa of Mercia, which were inscribed with the legend OFFA REX, "King Offa". The English silver penny was derived from another silver coin, the sceat, of 20 troy grains weight, which was in general circulation in Europe during the Middle Ages. In the 12th century, Henry II established the sterling silver standard for English coinage, of 92.5% silver and 7.5% copper, replacing the earlier use of fine silver in the Middle Ages. The coinage reform of 1816 set up a weight/value ratio and physical sizes for silver coins. Silver was eliminated from coins, except Maundy coins, in 1947.

Crown (British coin)

The British crown, the successor to the English crown and the Scottish dollar, came into being with the Union of the kingdoms of England and Scotland in 1707. As with the English coin, its value was five shillings.

Always a heavy silver coin weighing around one ounce, during the 19th and 20th centuries the crown declined from being a real means of exchange to being a coin rarely spent and minted for commemorative purposes only. In that format it has continued to be minted, even following decimalisation of the British currency in 1971. However, as the result of inflation the value of the coin was revised upwards in 1990 to five pounds.

Decimal Day

On 15 February 1971, known as Decimal Day, the United Kingdom and Ireland decimalised their currencies.

Under the old currency of pounds, shillings and pence, the pound was made up of 240 pence (denoted by the letter d for Latin denarius and now referred to as "old pence"), with 12 pence in a shilling and 20 shillings (denoted by s for Latin solidus) in a pound.

The loss of value of the currency meant that the "old" penny, with the same diameter as the US half-dollar, had become of relatively low value.

Decimal degrees

Decimal degrees (DD) express latitude and longitude geographic coordinates as decimal fractions and are used in many geographic information systems (GIS), web mapping applications such as OpenStreetMap, and GPS devices. Decimal degrees are an alternative to using degrees, minutes, and seconds (DMS). As with latitude and longitude, the values are bounded by ±90° and ±180° respectively.

Positive latitudes are north of the equator, negative latitudes are south of the equator. Positive longitudes are east of Prime Meridian, negative longitudes are west of the Prime Meridian. Latitude and longitude are usually expressed in that sequence, latitude before longitude.

Farthing (British coin)

The British farthing (​1⁄4d) coin, from "fourthing", was a unit of currency of one quarter of a penny, or ​1⁄960 of a pound sterling. It was minted in bronze, and replaced the earlier copper farthings. It was used during the reign of six monarchs: Victoria, Edward VII, George V, Edward VIII, George VI and Elizabeth II, ceasing to be legal tender in 1960. It featured two different designs on its reverse during its 100 years in circulation: from 1860 until 1936, the image of Britannia; and from 1937 onwards, the image of a wren. Like all British coinage, it bore the portrait of the monarch on the obverse.Before Decimal Day in 1971, there were 240 pence in one pound sterling. There were four farthings in a penny, 12 pence made a shilling, and 20 shillings made a pound. Values less than a pound were usually written in terms of shillings and pence, e.g., three shillings and six pence (3/6), pronounced "three and six" or "three and sixpence". Values of less than a shilling were simply written in pence, e.g., 8d, pronounced "eightpence". A price with a farthing in it would be written like this: (19/​11 1⁄4), pronounced "nineteen and elevenpence farthing".

The purchasing power of a farthing from 1860 to its demise in 1960 ranged between 2p to 12p (in 2017 GB Pound values).

Florin (British coin)

The British florin, or two shilling coin, was issued from 1849 until 1967, with a final issue for collectors dated 1970. Valued at one tenth of a pound (24 old pence), it was the last coin circulating immediately prior to decimalisation to be demonetised, in 1993, having for a quarter of a century circulated alongside the ten pence piece, identical in specifications and value.

The florin was introduced as part of an experiment in decimalisation that went no further at that time. The original florins, dated 1849, attracted controversy for omitting a reference to God from Queen Victoria's titles; that type is accordingly known as the "Godless florin", and was in 1851 succeeded by the "Gothic florin", for its design and style of lettering. Throughout most of its existence, the florin bore some variation of either the shields of the United Kingdom, or the emblems of its constituent nations on the reverse, a tradition broken between 1902 and 1910, when the coin featured a windswept figure of a standing Britannia.

In 1911, following the accession of George V, the florin regained the shields and sceptres design it had in the late Victorian Era, and kept that motif until 1937, when the national emblems were placed on it. The florin retained such a theme for the remainder of its run, though a new design was used from 1953, following the accession of Elizabeth II. In 1968, prior to decimalisation, the Royal Mint began striking the ten pence piece. The old two shilling piece remained in circulation until the ten pence piece was made smaller, and earlier coins, including the florin, were demonetised.


The gradian is a unit of measurement of an angle, equivalent to



{\textstyle {\frac {1}{400}}}

of a turn,



{\textstyle {\frac {9}{10}}}

of a degree, or



{\textstyle {\frac {\pi }{200}}}

of a radian. The gradian is defined as



{\textstyle {\frac {1}{100}}}

of the right angle (in other words, there are 100 gradians in the right angle), which implies a full turn being 400 gradians.It is also known as gon (from Greek γωνία/gōnía for angle), grad, or grade. In continental Europe, the French term centigrade was in use for one hundredth of a grad. This was one reason for the adoption of the term Celsius to replace centigrade as the name of the temperature scale.

Half crown (British coin)

The half crown was a denomination of British money, equivalent to two shillings and sixpence, or one-eighth of a pound. The half crown was first issued in 1549, in the reign of Edward VI. No half crowns were issued in the reign of Mary, but from the reign of Elizabeth I half crowns were issued in every reign except Edward VIII, until the coins were discontinued in 1967.

The half crown was demonetised (ahead of other pre-decimal coins) on 1 January 1970, the year before the United Kingdom adopted decimal currency on Decimal Day. During the English Interregnum of 1649–1660, a republican half crown was issued, bearing the arms of the Commonwealth of England, despite monarchist associations of the coin's name. When Oliver Cromwell was made Lord Protector of England, half crowns were issued bearing his semi-royal portrait. The half crown did not display its value on the reverse until 1893.

Halfpenny (British decimal coin)

The British decimal halfpenny (​1⁄2p) coin was introduced in February 1971, at the time of decimalisation, and was worth one two-hundredth of a pound sterling. It was ignored in banking transactions, which were carried out in units of 1p.

The decimal halfpenny had the same value as 1.2 pre-decimal pence, and was introduced to enable the prices of some low-value items to be more accurately translated to the new decimal currency. The possibility of setting prices including an odd half penny also made it more practical to retain the pre-decimal sixpence in circulation (with a value of ​2 1⁄2 new pence) alongside the new decimal coinage.

The halfpenny coin's obverse featured the profile of Queen Elizabeth II; the reverse featured an image of St Edward's Crown. It was minted in bronze (like the 1p and 2p coins). It was the smallest decimal coin in both size and value. The size was in proportion to the 1p and 2p coins. It soon became Britain's least favourite coin. The Treasury had continued to argue that the halfpenny was important in the fight against inflation (preventing prices from being rounded up). The coin was demonetised and withdrawn from circulation in December 1984.

Halfpenny (British pre-decimal coin)

The British pre-decimal halfpenny (​1⁄2d) coin, usually simply known as a halfpenny (pronounced HAY-pə-nee), historically occasionally also as the obol, was a unit of currency that equalled half of a penny or ​1⁄480 of a pound sterling. Originally the halfpenny was minted in copper, but after 1860 it was minted in bronze. It ceased to be legal tender in 1969, in the run-up to decimalisation. The halfpenny featured two different designs on its reverse during its years in circulation. From 1672 until 1936 the image of Britannia appeared on the reverse, and from 1937 onwards the image of the Golden Hind appeared. Like all British coinage, it bore the portrait of the monarch on the obverse."Halfpenny" was colloquially written ha’penny, and "​1 1⁄2d" was spoken as "a penny ha’penny" or three ha'pence . Before Decimal Day in 1971 there were 240 pence in one pound sterling. Twelve pence made a shilling, and twenty shillings made a pound. Values less than a pound were usually written in terms of shillings and pence, e.g. 42 pence would be three shillings and six pence (3/6), pronounced "three and six", whereas 3 shillings even would be "3s" or, on a sign in a shop, "3/-" (the dash usually being written instead of 0 for pence). Values of less than a shilling were simply written in pence, e.g. eightpence would be 8d (the "d" standing for the Latin word denarii (sing. denarius, a common coin in Roman Britain) .

ISO 2848

International standard ISO 2848 (Building construction – Modular coordination – Principles and rules, International Organization for Standardization, 1984) is an ISO standard used by the construction industry. It is based on multiples of 300 mm (30 cm) and 600 mm (60 cm). The numbers 300 and 600 were chosen because they are preferred numbers due to their large number of divisors – any multiple can be evenly divided into 2, 3, 4, 5, 6, 10, 12, 15, 20, 25, 30, etc., making them easy to use in mental arithmetic. This system is known as "modular coordination". A related standard is British Standard 6750.

List of British banknotes and coins

List of British banknotes and coins, with commonly used terms.

Penny (Australian coin)

The Australian penny was a coin of the Australian pound used in the Commonwealth of Australia prior to decimalisation in 1966. It was worth one-twelfth of an Australian shilling and 1/240 of an Australian pound. The coin was equivalent in its dimensions, composition and value to the British penny, as the two currencies were fixed at par.

The coin was first introduced in 1911, and stopped being minted in 1965, with the introduction of decimalisation. When decimalisation happened on 14 February 1966, the coin value was equal to 0.8333¢.

The obverse of the coin featured the reigning Australian monarch. Three were featured: George V, George VI and Elizabeth II. All of the pennies featuring George VI and Elizabeth II had a kangaroo on the reverse except for the 1965 penny it featured a Roman. The kangaroo image was on the Australian half-penny and has since been included on the dollar coin and the bullion silver kangaroo.

During the George VI era, coins minted at Perth had a dot either at the end of the word "PENNY", after the word "AUSTRALIA" or in between the "K" and "G" above the end of the kangaroo's tail, while coins from Melbourne did not have a dot. An "I" under the bust of George VI denoted being minted in India. A "PL" mintmark after "PENNY" denoted minting in London, England. This continued through the end of the coin's lifetime.

Penny (British pre-decimal coin)

The pre-decimal penny (1d) was a coin worth 1/240 of a pound sterling. Its symbol was d, from the Roman denarius. It was a continuation of the earlier English penny, and in Scotland it had the same monetary value as one pre-1707 Scottish shilling. The penny was originally minted in silver, but from the late 18th century it was minted in copper, and then after 1860 in bronze.

The plural of "penny" is "pence" when referring to a quantity of money and "pennies" when referring to a number of coins. Thus 8d is eight pence, but "eight pennies" means specifically eight individual penny coins.

Before Decimal Day in 1971 twelve pence made a shilling, and twenty shillings made a pound, hence 240 pence in one pound. Values less than a pound were usually written in terms of shillings and pence, e.g. 42 pence would be three shillings and sixpence (3/6), pronounced "three and six". Values of less than a shilling were simply written in terms of pence, e.g. eight pence would be 8d.

This version of the penny was made obsolete in 1971 by decimalisation, and was replaced by the decimal penny, worth 2.4 old pence.


Redenomination is the process of changing the face value of banknotes or coins used in circulating currency. It may be done because inflation has made the currency unit so small that only large denominations of the currency are circulated. In such cases the name of the currency may change or the original name may be used with a temporary qualifier such as "new". Redenomination may be done for other reasons such as adopting a new currency as with the Euro or decimalisation. The article deals with these various types of redenomination in detail.

Shilling (Australian)

The Australian Shilling was a coin of the Commonwealth of Australia prior to decimalisation. The coin was minted from 1910 until 1963, excluding 1923, 1929, 1930, 1932, 1938, 1947, 1949 and 1951. After decimalisation on 14 February 1966, it was equal to 10c.

During World War II, between 1942–1944, shilling production was supplemented by coinage produced at the San Francisco branch of the United States Mint, which bear a small S below the ram's head.

Shilling (British coin)

The shilling (1/-) was a coin worth one twentieth of a pound sterling, or twelve pence. It was first minted in the reign of Henry VII as the testoon, and became known as the shilling from the Old English scilling, sometime in the mid-sixteenth century, circulating until 1990. The word bob was sometimes used for a monetary value of several shillings, e.g. "ten bob note". Following decimalisation on 15 February 1971 the coin had a value of five new pence. It was made from silver from its introduction in or around 1503 until 1947, and thereafter in cupronickel.

Prior to Decimal Day in 1971 there were 240 pence in one pound sterling. Twelve pence made a shilling, and twenty shillings made a pound. Values less than a pound were usually written in terms of shillings and pence, e.g. forty-two pence would be three shillings and six pence (3/6), pronounced "three and six". Values of less than a shilling were simply written in terms of pence, e.g. eight pence would be 8d.

Although the coin was not minted until the sixteenth century, the value of a shilling had been used for accounting purposes since the Anglo-Saxon period. Originally, a shilling was deemed to be the value of a cow in Kent, or a sheep elsewhere. The value of one shilling equalling 12d was set by the Normans following the conquest; prior to this various Anglo-Saxon coins equalling 4, 5, and 12 pence had all been known as shillings.

Sixpence (British coin)

The sixpence (6d; ), sometimes known as a tanner or sixpenny bit, is a coin that was worth one-fortieth of a pound sterling, or six pence. It was first minted in the reign of Edward VI and circulated until 1980. Following decimalisation in 1971 it had a value of ​2 1⁄2 new pence. The coin was made from silver from its introduction in 1551 to 1947, and thereafter in cupronickel.

Prior to Decimal Day in 1971 there were 240 pence in one pound sterling. Twelve pence made a shilling, and twenty shillings made a pound. Values less than a pound were usually written in shillings and pence, e.g. 42 old pence (​17 1⁄2p) would be three shillings and sixpence (3/6), often pronounced "three and six". Values of less than a shilling were simply written in terms of pence, e.g. eight pence would be 8d ('d' for denarius).

Thousandth of an inch

A thousandth of an inch is a derived unit of length in an inch-based system of units. Equal to ​1⁄1000 of an inch, it is normally referred to as a thou , a thousandth, or (particularly in the United States) a mil.

The plural of thou is also thou (thus one hundredth of an inch is "10 thou"), while the plural of mil is mils (thus "10 mils"). Note that thou is pronounced with an unvoiced th, like the start of thousand, not voiced like the archaic word for you. The words are shortened forms of the English and Latin words for "thousand" (mille). The US customary mil can be confused with the millimetre, which is the standard meaning for "mil" or "mils" (plural) in British English and European engineering circles. This can cause problems with spoken dimensions or with those who are not familiar with alternative uses of the term. One US mil is approximately ​1⁄40 millimetre at 0.0254 mm, or 25.4 micrometres (μm).

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