Hecto or hecta is a unit prefix in the metric system denoting a factor of one hundred. It was adopted as a multiplier in 1795, and comes from the Greek ἑκατόν hekaton, meaning hundred. Its unit symbol in the International System of Units (SI) is the lower case letter h.
It is rarely used, except in certain specific applications:
In mathematics, a power of 10 is any of the integer powers of the number ten; in other words, ten multiplied by itself a certain number of times. By definition, the number one is a power (the zeroth power) of ten. The first few powers of ten are:
In decimal notation the nth power of ten is written as '1' followed by n zeroes. It can also be written as 10n or as 1En in E notation. See order of magnitude and orders of magnitude (numbers) for named powers of ten. There are two conventions for naming positive powers of ten, called the long and short scales. Where a power of ten has different names in the two conventions, the long scale name is shown in brackets.
A metric prefix or SI prefix is a unit prefix that precedes a basic unit of measure to indicate a decadic multiple or fraction of the unit. Each prefix has a unique symbol that is prepended to the unit symbol. The prefix kilo-, for example, may be added to gram to indicate multiplication by one thousand; one kilogram is equal to one thousand grams. The prefix centi-, likewise, may be added to metre to indicate division by one hundred; one centimetre is equal to one hundredth of a metre.
Decimal multiplicative prefixes have been a feature of all forms of the metric system with many dating back to the system's introduction in the 1790s. Metric prefixes have even been pre-pended to non-metric units. Today the prefixes are standardized for use in the International System of Units (SI) by the International Bureau of Weights and Measures in resolutions dating from 1960 to 1991.