Unit of account L.S.D units in ratio 240:12:1. The Florentine gold florin, the French franc and the electoral rheingulden all became pounds (240 denari) of account. Units of account would often survive over 100 years despite the original coins changing composition and availability (e.g. the Castilian maravedi). A modern unit of account is the European Currency Unit, used in the European Union from 1979 to 1998; its replacement in 1999, the Euro, was also just a unit of account until the introduction of notes and coins in 2002. Unit of account is the main way of calculating a carrier or ship owner's liability
Currency pair = Cable = GBP/USD. The currency pairs that do not involve USD are called "cross currency pairs", such as GBP/JPY. Pairs that involve the euro are often called "euro crosses", such as EUR/GBP. Currencies are traded in fixed contract sizes, specifically called lot sizes, or multiples thereof. The standard lot size is 100,000 units. Many retail trading firms also offer 10,000-unit (mini lot) trading accounts and a few even 1,000-unit (micro lot). The officially quoted rate is a spot price. In a trading market however, currencies are offered for sale at an offering price (the "ask price"), and traders looking