
Inmathematics, apower of 10 is any of theintegerpowers of the numberten; in other words, tenmultiplied by itself a certain number of times (when the power is a positive integer). By definition, the number one is a power (thezeroth power) of ten. The first few non-negative powers of ten are:
Indecimal notation thenth power of ten is written as '1' followed byn zeroes. It can also be written as 10n or as 1En inE notation. Seeorder of magnitude andorders of magnitude (numbers) for named powers of ten. There are two conventions for naming positive powers of ten, beginning with 109, called thelong 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:
| Name | Alternate names | Power | Number | SI symbol | SI prefix |
|---|---|---|---|---|---|
| one | 0 | 1 | |||
| ten | 1 | 10 | da | deca | |
| hundred | 2 | 100 | h | hecto | |
| thousand | 3 | 1,000 | 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 | 10100 |
For further examples, seeNames 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.
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:
| 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 |
The number googol is 10100. The term was coined by 9-year-old Milton Sirotta, nephew of American mathematicianEdward Kasner. It was popularized in Kasner's 1940 bookMathematics 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 is a way of writing numbers of very large and very small sizes compactly.
A number written in scientific notation has asignificand (sometime called a mantissa) multiplied by a power of ten.
Sometimes written in the form:
Or more compactly as:
This is generally used to denote powers of 10. Wheren is positive, this indicates the number of zeros after the number, and where then is negative, this indicates the number of decimal places before the number.
As an example:
The notation ofmEn, known asE notation, is used in computer programming, spreadsheets and databases, but is not used in scientific papers.