i just looked it up. some countries use 10^9 and some use 10^12 as a billion. it depends on what country you are in.
To sum up, most european countries still define a billion as 10^12. the brits and the commonwealth countries was using 10^12 before 1974, but after then they define a billion as 10^9. Canada uses both.
The term short scale is for 10^9, long scale is 10^12
this is from wikipedia:
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Current usage
Short scale countries and regions
106 = one million, 109 = one billion / one milliard, 1012 = one trillion, etc.
English language-speaking countries and regions
Most English-language countries use the short scale with 109 = billion. For example:
Australia
Hong Kong (English-speaking)
Ireland (English-speaking)
New Zealand
Philippines (English-speaking): Some short-scale words have been adopted into Filipino.
Singapore (English-speaking)
United Kingdom (see Wales below)
United States
[edit] Other short scale languages and countries
Other countries also use a word similar to trillion to mean 1012, etc. While a few of these countries use a word similar to billion to mean 109, most have kept a traditional long scale word similar to "milliard" for 109. Some examples of short scale use, and the words used for 109 and 1012, are:
Brazil (bilhão, trilhão)
Bulgaria (милиард miliard, трилион trilion)
Estonia (miljard, triljon)
Indonesia (milyar, triliun) [15]
Iran (میلیارد milyard, )
Israel (מיליארד millyard, )
Latvia (miljards, )
Lithuania (milijardas, trilijonas)
Romania (miliard / bilion, trilion)
Russia (миллиард milliard, триллион trillion)
Turkey (milyar, trilyon)
Wales (biliwn, triliwn)
[edit] Short scale use but with other terminology
Greece (εκατομμύριο ekatommyrio "hundred-myriad" = 106; δισεκατομμύριο disekatommyrio "bi-hundred-myriad" = 109; τρισεκατομμύριο trisekatommyrio "tri-hundred-myriad" = 1012; τετράκις εκατομμύριο tetrakis ekatommyrio "tetra-hundred-myriad" = 1015, and so on.) [16]
[edit] Long scale countries
106 = one million, 109 = one milliard / thousand million, 1012 = one billion, 1015 = one billiard / thousand billion, 1018 = one trillion, etc.
The traditional long scale is used by most Continental European countries and by most other countries whose languages derive from Continental Europe (with the notable exceptions of Greece, Romania, and Brazil). Many of these countries use a word similar to milliard to mean 109, and/or a word similar to billion to mean 1012. Some examples of long scale use, and the words used for 109 and 1012, are:
Andorra (Catalan: miliard or typ. mil milions, bilió)
Argentina (Spanish: mil millones, billón)
Austria (Austrian German: Milliarde, Billion)
Belgium (French: milliard, billion; Dutch: miljard, biljoen; German: Milliarde, Billion)
Bosnia and Herzegovina (Serbian: милијарда milijarda, Билион bilion; Croatian: milijarda, bilijun)
Chile (Spanish: mil millones, billón)
Colombia (Spanish: mil millones, billón)
Costa Rica (Spanish: mil millones, billón)
Croatia (milijarda, bilijun)
Czech Republic (miliarda, bilion)
Denmark (milliard, billion)
Dominican Republic (Spanish: mil millones, billón)
Ecuador (Spanish: mil millones, billón)
El Salvador (Spanish: mil millones, billón)
Finland (Finnish: miljardi, biljoona; Swedish: miljard, biljon)
France (milliard, billion)
Germany (Milliarde, Billion)
Guatemala (Spanish: millardo, billón)
Hungary (milliárd, billió or ezer milliárd)
Iceland (milljarður, billjón)
Italy (miliardo, bilione) [14]
Liechtenstein (German: Milliarde, Billion)
Luxembourg (Luxembourgish: milliard, billioun; French: milliard, billion; German: Milliarde, Billion)
Mexico (Spanish: mil millones or millardo, billón)
Monaco (French: milliard, billion)
Netherlands (miljard, biljoen)
Norway (milliard, billion)
Paraguay (Spanish: mil millones, billón)
Peru (Spanish: mil millones, billón)
Poland (miliard, bilion)
Portugal (mil milhões or milhar de milhões, bilião)
Serbia (милијарда milijarda, Билион bilion)
Slovakia (miliarda, bilión)
Slovenia (milijarda, bilijon)
Spain (Spanish: millardo or typ. mil millones, billón)
Sweden (miljard, biljon)
Switzerland (French: milliard, billion; German: Milliarde, Billion; Italian: miliardo, bilione)
Uruguay (Spanish: mil millones or millardo, billón)
Venezuela(Spanish: mil millones or millardo, billón)
[edit] Both long and short scales countries
Country Short scale usage Long scale usage
Canada Canadian English (billion = 109, trillion = 1012) Canadian French (milliard = 109, billion = 1012).
Puerto Rico in economic and technical matters (billón = 109, trillón = 1012) in Latin American publications outside Puerto Rico (millardo or mil millones = 109, billón = 1012)
South Africa South African English (billion = 109, trillion = 1012) Afrikaans (miljard = 109, biljoen = 1012) [17] [18].