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 (when the power is a positive integer). By definition, the number one is a power (the zeroth power) of ten. The first few non-negative powers of ten are:

Visualisation of powers of 10 from one to 1 trillion.
1, 10, 100, 1,000, 10,000, 100,000, 1,000,000, 10,000,000... (sequence A011557 in the OEIS)

Positive powers

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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, beginning with 109, 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 parentheses.

The positive 10 power related to a short scale name can be determined based on its Latin name-prefix using the following formula: 10[(prefix-number 1) × 3]

Examples:

  • billion = 10[(2 1) × 3] = 109
  • octillion = 10[(8 1) × 3] = 1027
Name Alternate names Power Number SI symbol SI prefix
one 0 1
ten 1 10 da (D) deca
hundred 2 100 h (H) hecto
thousand 3 1,000 k (K) kilo
ten thousand myriad (Greek) 4 10,000
hundred thousand lakh (India) 5 100,000
million 6 1,000,000 M mega
ten million crore (India) 7 10,000,000
hundred million 8 100,000,000
billion milliard (LS) 9 1,000,000,000 G giga
trillion billion (LS) 12 1,000,000,000,000 T tera
quadrillion billiard (LS) 15 ... P peta
quintillion trillion (LS) 18 E exa
sextillion trilliard (LS) 21 Z zetta
septillion quadrillion (LS) 24 Y yotta
octillion quadrilliard (LS) 27 R ronna
nonillion quintillion (LS) 30 Q quetta
decillion quintilliard (LS) 33
googol 100
centillion 303
googolplex googol

For further examples, see Names of large numbers. Numbers larger than about a trillion are rarely referred to by name or written out as digits, but instead are typically described with exponent notation.

Negative powers

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The sequence of powers of ten can also be extended to negative powers.

Similar to the positive powers, the negative power of 10 related to a short scale name can be determined based on its Latin name-prefix using the following formula: 10−[(prefix-number 1) × 3]

Examples:

  • billionth = 10−[(2 1) × 3] = 10−9
  • quintillionth = 10−[(5 1) × 3] = 10−18
Name Power Number SI symbol SI prefix
one 0 1
tenth −1 0.1 d deci
hundredth −2 0.01 c centi
thousandth −3 0.001 m milli
ten-thousandth −4 0.000 1
hundred-thousandth −5 0.000 01
millionth −6 0.000 001 μ micro
billionth −9 0.000 000 001 n nano
trillionth −12 ... p pico
quadrillionth −15 f femto
quintillionth −18 a atto
sextillionth −21 z zepto
septillionth −24 y yocto
octillionth −27 r ronto
nonillionth −30 q quecto
decillionth −33

Googol and googolplex

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The number googol is 10100. The term was coined by 9-year-old Milton Sirotta, nephew of American mathematician Edward Kasner. It was popularized in Kasner's 1940 book Mathematics and the Imagination, where it was used to compare and illustrate very large numbers. Googolplex, a much larger power of ten (10 to the googol power, or 1010100), was also introduced in that book.

Scientific notation

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Scientific notation is a way of writing numbers of very large and very small sizes compactly when precision is less important.

A number written in scientific notation has a significand (sometime called a mantissa) multiplied by a power of ten.

Sometimes written in the form:

m × 10n

Or more compactly as:

10n

This is generally used to denote powers of 10. Where n is positive, this indicates the number of zeros after the number, and where the n is negative, this indicates the number of decimal places before the number.

As an example:

105 = 100,000[1]
10−5 = 0.00001[2]

The notation of mEn, known as E notation, is used in computer programming, spreadsheets and databases, but is not used in scientific papers.

See also

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Further reading

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Video
  • Powers of Ten (1977). Nine-minute film. US Public Broadcasting Service (PBS), made by Charles and Ray Eames. "An adventure in magnitudes. Starting at a picnic by the lakeside in Chicago, this film transports the viewer to the outer edges of the universe. Every ten seconds we view the starting point from ten times farther out until our own galaxy is visible only as a speck of light among many others. Returning to Earth with breathtaking speed, we move inward - into the hand of the sleeping picnicker - with ten times more magnification every two seconds. Our journey ends inside a proton of a carbon atom within a DNA molecule in a white blood cell."

References

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  1. ^ "Powers of 10". www.mathsteacher.com.au. Retrieved 2020-03-17.
  2. ^ "Powers of Ten". hesperia.gsfc.nasa.gov. Retrieved 2020-03-17.