Which currency is the most traded in the world, involved in approximately 88% of all foreign exchange transactions? This currency is the primary reserve currency of most central banks worldwide and is used for international trade in commodities like oil, gold, and wheat. Its symbol is "$" and its code is USD. Approximately 58% of all global foreign exchange reserves are held in this currency. Many countries use it as their official currency (Ecuador, El Salvador, Zimbabwe) or peg their own currency to it. The currency is issued by the Federal Reserve System, established in 1913. Over 60% of all banknotes in circulation are outside its home country. The most common bill is the $100 bill, with an estimated 80% held outside the country. It is the world's primary "fiat currency" (not backed by gold since 1971).

Which currency, first minted in the 8th century (over 1,200 years ago), is the oldest currency still in continuous use? This currency originated as a silver penny in the kingdom of Mercia under King Offa (757-796 AD). The pound symbol "£" comes from the Latin word "libra" (scale). The currency was decimalized in 1971, changing from 20 shillings per pound (each shilling worth 12 pennies) to 100 pence per pound. The Bank of England was established in 1694 and has issued banknotes for over 300 years. The currency is used in its home country and several overseas territories. The currency code is GBP. The banknotes feature famous historical figures like Sir Winston Churchill, Jane Austen, JMW Turner, and Alan Turing. Polymer banknotes (plastic) were introduced in 2016. The currency remains one of the highest-valued major currencies in the world.

Which currency is officially used by the most countries (19 out of 27 European Union member states and 4 non-EU countries)? This currency was introduced as an electronic currency for banking in 1999, and physical coins and banknotes entered circulation in 2002. It replaced 12 national currencies on January 1, 2002. The currency is managed by the European Central Bank (ECB) in Frankfurt, Germany. Countries must meet strict "Maastricht criteria" to join, including low inflation, stable exchange rates, and low government debt. The currency's symbol "€" is inspired by the Greek letter epsilon (Є) and represents the first letter of "Europe." The currency is used by over 340 million Europeans daily. It is the second-most traded currency after the US Dollar. Banknotes show architectural styles (Classical, Romanesque, Gothic, Renaissance, Baroque, Modern) but no real buildings.

Which currency has the highest value per unit (one unit buys the most US Dollars)? This Middle Eastern country's currency is pegged to the US Dollar at a fixed rate of 1 unit = $3.64 USD. It has been pegged since 1973. The country is a small, oil-rich nation on the Arabian Peninsula. Unlike most currencies that are divided into 100 subunits, this currency is divided into 1,000 fils. The country has no income tax and uses its oil wealth to provide free healthcare, education, and housing to citizens. The currency is not commonly traded internationally because of its peg, but its high value makes it a popular joke currency – "If I had a [currency] for every time..." The currency code is KWD. The second-highest valued currency is the Bahraini Dinar (BHD) at $2.65 USD, followed by the Omani Rial (OMR) at $2.60 USD.

Which country's currency has experienced such extreme inflation that 1 US Dollar equals over 2,500 units of its currency? This country in southern Africa had its currency collapse in the late 2000s due to hyperinflation. At the peak in 2008, inflation reached 89.7 sextillion percent (89.7 followed by 20 zeros). The government printed a 100 trillion dollar banknote – worth about US$40 at the time, now a collector's item. The country abandoned its currency in 2009 and now uses multiple foreign currencies including the US Dollar, South African Rand, and the Chinese Renminbi. However, the government reintroduced a new version of its currency in 2019, but it is still very unstable. The country is known for Victoria Falls, safaris, and being the former British colony of Rhodesia. The currency code is ZWL.

Which country was the first to introduce polymer (plastic) banknotes in 1988, and continues to produce some of the most advanced and beautiful banknotes in the world? This country replaced paper banknotes with polymer to increase durability and prevent counterfeiting. Polymer notes last 2.5 times longer than paper notes and can be washed in a washing machine without damage. The notes have transparent windows with holograms and intricate designs. The country's $5 note features Sir John Monash and the Centenary of WWI, the $10 note features Banjo Paterson and Dame Mary Gilmore, the $20 note features Mary Reibey and John Flynn, the $50 note features Edith Cowan and David Unaipon, and the $100 note features Dame Nellie Melba and Sir John Monash. The notes are almost impossible to counterfeit. The country's currency code is AUD. The country also invented the "Holey Dollar" in 1813 (a coin with a hole in it).

Which currency is the most counterfeited in the world, with an estimated 1 in 10,000 banknotes being fake? This currency is the world's most traded currency, which makes it the most attractive target for counterfeiters. The $100 bill (the "Benjamin") is the most counterfeited denomination. To combat counterfeiting, the country redesigned its banknotes with advanced security features including color-shifting ink, watermarks, security threads, microprinting, and 3D security ribbons. The newest $100 bill (introduced 2013) has a blue 3D security ribbon and a "bell in the inkwell" that changes from copper to green when tilted. Despite these features, professional counterfeiters still attempt to replicate it. The Secret Service (originally created to combat counterfeiting) is responsible for protecting this currency. About 60% of counterfeit notes are produced outside the country, often by criminal organizations.

Which country has the highest denomination banknote in regular circulation: the 100,000 [currency] note worth approximately US$635? This Southeast Asian country's large denominations are a result of past inflation, though the country is now a stable emerging economy. The banknotes are very large physically – the 100,000 note is 162 mm x 65 mm (about 6.4 inches x 2.6 inches). Other high denominations include 50,000 and 20,000 notes. The country revalued its currency in 2016 by removing 5 zeros from the old currency (10,000 old = 1 new). However, the "new" currency still has high denominations. The country is famous for its batik textiles, coffee (Kopi Luwak), and the world's largest Buddhist temple (Borobudur). The currency code is IDR. The second-largest note is Vietnam's 500,000 Dong note (worth about US$21).

Which small European country uses the Euro but does not have its own national central bank and is not a member of the European Union? This microstate, located in the Pyrenees mountains between France and Spain, has a population of about 77,000 people. It is not a member of the EU, but it has a monetary agreement with the EU allowing it to use the Euro as its official currency. Because it is not in the EU, it cannot mint its own Euro coins (unlike Monaco, San Marino, and Vatican City, which can mint limited quantities). The country uses regular Euro coins and banknotes from other countries. The country is famous for tourism (skiing in winter, hiking in summer), duty-free shopping, and being the setting for a classic novel of the same name. Its official language is Catalan. The country's two heads of state are the President of France and the Bishop of Urgell (Spain).

Which country was the first to adopt a decimal currency system (1 main unit = 100 subunits) in 1792? This country's currency system was established by the Coinage Act of 1792, creating the US Dollar (based on the Spanish dollar) divided into 100 cents. Before this, most currencies used complex systems like pounds-shillings-pence (1 pound = 20 shillings = 240 pence). Thomas Jefferson proposed the decimal system, arguing it would make calculations easier for ordinary people. The US Mint was established in Philadelphia in 1792, and the first coins were struck in 1793. The decimal system was so successful that almost every country has since adopted it. The last major country to decimalize was the United Kingdom in 1971. The word "dollar" comes from the German "Thaler" (silver coin). The US currency is also the first to use "In God We Trust" on coins (1864) and banknotes (1957).