Conventions and notations

• France is the home of the International System of Units (the metric system). Some pre-metric units are still used, essentially the livre (a unit of weight equal to half a kilogram) and the quintal (a unit of weight equal to 100 kilograms).
• In mathematics, France uses the infix notation like most countries. For large numbers the long scale is used. Thus, the French use the word billion for the number 1,000,000,000,000, which in countries using short scale is called a trillion. However, there exists a French word, milliard, for the number 1,000,000,000, which in countries using the short scale is called a billion. Thus, despite the use of the long scale, one billion is called un milliard (“one milliard”) in French, and not mille millions (“one thousand million”). It should also be noted that names of numbers above the milliard are rarely used. Thus, one trillion will most often be called mille milliards (“one thousand milliard”) in French, and rarely un billion.
• In the French numeral notation, the comma (,) is the Decimal separator, whereas the dot (.) is used between each group of three digits especially for big numbers. A space can also be used to separate each group of three digits especially for small numbers. Thus three thousand five hundred and ten may be written as 3 510 whereas fifteen million five hundred thousand and thirty-two may be written as 15.500.032. In finance, the currency symbol is used as a decimal separator or put after the number. For example, €25,048.05 is written either 25 048€05 or 25 048,05 € (always with an extra space between the figure and the currency symbol).
• In computing, a bit is called a bit yet a byte is called an octet (from the Latin root octo, meaning “8”). SI prefixes are used.
• 24-hour clock time is used, with h being the separator between hours and minutes (for example 2:30 p.m. is 14h30).
• The all-numeric form for dates is in the order day-month-year, using a slash as the separator (example: 31/12/1992 or 31/12/92).