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This is a list of the names of small decimal numbers in English.
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This is a list of the names of small decimal numbers in English.
The following table lists the names of small numbers used in the long and short scales, along with the power of 10, engineering notation, and International System of Units (SI) symbols and prefixes. [1] [ page needed ] [2] [ page needed ] [3] [ page needed ] [4] [5] [6] [7]
| Power of ten | Engineering notation [ citation needed ] | Short scale (U.S. and modern British) | Long scale (continental Europe, archaic British, and India) | SI prefix | SI symbol |
|---|---|---|---|---|---|
| 100 | 1 | One | |||
| 10−1 | 100×10−3 | One Tenth | deci- | d | |
| 10−2 | 10×10−3 | One One-Hundredth | centi- | c | |
| 10−3 | 1×10−3 | One One-Thousandth | milli- | m | |
| 10−6 | 1×10−6 | One One-Millionth | micro- | µ | |
| 10−9 | 1×10−9 | One One-Billionth | One One-Milliardth | nano- | n |
| 10−12 | 1×10−12 | One One-Trillionth | One One-Billionth | pico- | p |
| 10−15 | 1×10−15 | One One-Quadrillionth | One One-Billiardth | femto- | f |
| 10−18 | 1×10−18 | One One-Quintillionth | One One-Trillionth | atto- | a |
| 10−21 | 1×10−21 | One One-Sextillionth | One One-Trilliardth | zepto- | z |
| 10−24 | 1×10−24 | One One-Septillionth | One One-Quadrillionth | yocto- | y |
| 10−27 | 1×10−27 | One One-Octillionth | One One-Quardilliardth | ronto- | r |
| 10−30 | 1×10−30 | One One-Nonillionth | One One-Quintillionth | quecto- | q |
| 10−33 | 1×10−33 | One One-Decillionth | One One-Quintilliardth | — | — |
| 10−36 | 1×10−36 | One One-Undecillionth | One One-Sextillionth | — | — |
| 0 | 1×10−∞ | Zero | |||
| –1 | –1 | Negative One | |||
| −∞ | undefined | Negative Infinity | |||
A binary prefix is a unit prefix that indicates a multiple of a unit of measurement by an integer power of two. The most commonly used binary prefixes are kibi (symbol Ki, meaning 210 = 1024), mebi (Mi, 220 = 1048576), and gibi (Gi, 230 = 1073741824). They are most often used in information technology as multipliers of bit and byte, when expressing the capacity of storage devices or the size of computer files.
The calorie is a unit of energy that originated from the caloric theory of heat. The large calorie, food calorie, dietary calorie, or kilogram calorie is defined as the amount of heat needed to raise the temperature of one kilogram of water by one degree Celsius. The small calorie or gram calorie is defined as the amount of heat needed to cause the same increase in one gram of water. Thus, 1 large calorie is equal to 1000 small calories.
Giga ( or ) is a unit prefix in the metric system denoting a factor of a short-scale billion or long-scale milliard (109 or 1,000,000,000). It has the symbol G.
The kilogram is the base unit of mass in the International System of Units (SI), having the unit symbol kg. It is a widely used measure in science, engineering and commerce worldwide, and is often simply called a kilo colloquially. It means 'one thousand grams'.
K, or k, is the eleventh letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is kay, plural kays. The letter K usually represents the voiceless velar plosive.
The kilobyte is a multiple of the unit byte for digital information. The International System of Units (SI) defines the prefix kilo as a multiplication factor of 1000 (103); therefore, one kilobyte is 1000 bytes. The internationally recommended unit symbol for the kilobyte is kB.
The litre or liter is a metric unit of volume. It is equal to 1 cubic decimetre (dm3), 1000 cubic centimetres (cm3) or 0.001 cubic metre (m3). A cubic decimetre occupies a volume of 10 cm × 10 cm × 10 cm and is thus equal to one-thousandth of a cubic metre.
The micrometre as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer, also commonly known by the non-SI term micron, is a unit of length in the International System of Units (SI) equalling 1×10−6 metre ; that is, one millionth of a metre.
The International System of Units, internationally known by the abbreviation SI, is the modern form of the metric system and the world's most widely used system of measurement. Coordinated by the International Bureau of Weights and Measures it is the only system of measurement with an official status in nearly every country in the world, employed in science, technology, industry, and everyday commerce.
A metric prefix is a unit prefix that precedes a basic unit of measure to indicate a multiple or submultiple of the unit. All metric prefixes used today are decadic. Each prefix has a unique symbol that is prepended to any 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 milli-, likewise, may be added to metre to indicate division by one thousand; one millimetre is equal to one thousandth of a metre.
The tonne is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton in the USA to distinguish it from the non-metric units of the short ton and the long ton. It is equivalent to approximately 2204.6 pounds, 1.102 short tons, and 0.984 long tons. The official SI unit is the megagram, a less common way to express the same amount.
The kilometre, spelt kilometer in American English and Philippine English, is a unit of length in the International System of Units (SI), equal to one thousand metres. It is the preferred measurement unit to express distances between geographical places on land in most of the world; notable exceptions are the United States and the United Kingdom where the statute mile is used.
The hectometre or hectometer is a unit of length in the International System of Units (SI), equal to one hundred metres and to one tenth of a kilometre. The word comes from a combination of "metre" and the SI prefix "hecto-", meaning "hundred". It is not commonly used in English. A football field is approximately 1 hectometre in length. The hectare (ha), a common metric unit for land area, is equal to one square hectometre (hm2).
Two naming scales for large numbers have been used in English and other European languages since the early modern era: the long and short scales. Most English variants use the short scale today, but the long scale remains dominant in many non-English-speaking areas, including continental Europe and Spanish-speaking countries in Latin America. These naming procedures are based on taking the number n occurring in 103n+3 or 106n and concatenating Latin roots for its units, tens, and hundreds place, together with the suffix -illion.
The long and short scales are two of several naming systems for integer powers of ten which use some of the same terms for different magnitudes.
Myria- (symbol my) is a now obsolete decimal metric prefix denoting a factor of 104 (ten thousand). It originates from the Greek μύριοι (mýrioi) (myriad). The prefix was part of the original metric system adopted by France in 1795, but was not adopted when the SI prefixes were internationally adopted by the 11th CGPM conference in 1960.
A unit prefix is a specifier or mnemonic that is prepended to units of measurement to indicate multiples or fractions of the units. Units of various sizes are commonly formed by the use of such prefixes. The prefixes of the metric system, such as kilo and milli, represent multiplication by positive or negative powers of ten. In information technology it is common to use binary prefixes, which are based on powers of two. Historically, many prefixes have been used or proposed by various sources, but only a narrow set has been recognised by standards organisations.
Numeral or number prefixes are prefixes derived from numerals or occasionally other numbers. In English and many other languages, they are used to coin numerous series of words. For example:
The hectare is a non-SI metric unit of area equal to a square with 100-metre sides (1 hm2), that is, 10,000 square meters, and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. An acre is about 0.405 hectares and one hectare contains about 2.47 acres.
The angstrom or ångström is a metric unit of length equal to 10−10 m; that is, one ten-billionth (US) of a metre, a hundred-millionth of a centimetre, 0.1 nanometre, or 100 picometres. Its symbol is Å, a letter of the Swedish alphabet. The unit is named after the Swedish physicist Anders Jonas Ångström (1814–1874).
