Trillions

Trillions is a term used for very large numbers. In modern English, a trillion most commonly means 10^12, that is, one thousand billion. In the long scale system, historically used in some European countries, a trillion denotes 10^18 (one million billion). Because the long and short scales assign different values to large-number names, the exact meaning of trillions can vary by country and historical period.

Etymology and naming: The word trillion comes from the French trillion, which itself is built from the prefix tri- meaning three and the suffix -illion, related to the word million. The precise numeric value attached to trillions has reflected the larger scale in use at the time and place, leading to the short-scale convention of 10^12 in much of the English-speaking world today.

Numeric examples: 1 trillion equals 1,000,000,000,000 in the short scale. In the long scale historically used in parts of Europe, 1 trillion would be 1,000,000,000,000,000,000. This contrast extends to other large-number names such as billion, with the short scale using 10^9 and the long scale using 10^12 for a billion.

Usage and context: Trillions are used to describe extremely large quantitative figures in economics, astronomy, demography, and data storage contexts (for example, notes about national debts, counts of stars, or data measured in trillions of bytes). In scientific writing, explicit scientific notation is often preferred to avoid ambiguity.

See also: short scale, long scale, large-number naming conventions.