How many people live in China? How big is the US national debt? What is the age of the Earth? Answers to these questions are different in various languages and sometimes it is not only a matter of language. There is the matter of using different large-number naming systems in various countries and it is another distinction between the English-speaking and European world.
There are two systems:
- a short scale which is used in the USA and UK, where one billion means one thousand million (1,000,000,000),
- a long scale which is used in most European countries, where milliard means a thousand million (1,000,000,000) and billion is a million million (1,000,000,000,000).
The whole world is divided by these two systems. The short scale is for example used in Brazil, Arabic countries, Russia and Australia. The long scale is applied in Spanish-speaking countries like in the South America (except Brazil) and in Mexico. Countries like China, India, Japan and some other Asian countries use other naming systems associated with their languages.
Some countries only switched to the short scale quite recently. The UK switched into the short scale in 1974, so they decided to join the system used by its bigger brother the USA than to use the system from closer countries like France, Germany or Spain.
From a strictly mathematical point of view the long scale is more logical. For example, “centi” in the metric system means “hundred” and centillion in long scale is 1,000,000 to the power of one hundered, and there are no such numbers in the short scale.