Editing Scientific notation (section)

=== E notation <span class="anchor" id="Q notation"></span> ===
{| class="wikitable" style="float:right; margin: 0.5em 0 1.3em 1.4em"
!Explicit notation
!E notation
|-
|{{val|2E0}}
|{{codett|2E0}}
|-
|{{val|3E2}}
|{{codett|3E2}}
|-
|{{val|4.321768E3}}
|{{codett|4.321768E3}}
|-
|{{val|-5.3E4}}
|{{codett|-5.3E4}}
|-
|{{val|6.72E9}}
|{{codett|6.72E9}}
|-
|{{val|2E-1}}
|{{codett|2E-1}}
|-
|{{val|9.87E2}}
|{{codett|9.87E2}}
|-
|{{val|7.51E-9}}
|{{codett|7.51E-9}}
|}

[[Calculator]]s and [[computer program]]s typically present very large or small numbers using scientific notation, and some can be configured to uniformly present all numbers that way. Because [[superscript]] exponents like 10<sup>7</sup> can be inconvenient to display or type, the letter "E" or "e" (for "exponent") is often used to represent "times ten raised to the power of", so that the notation {{nowrap|''m''&hairsp;E&hairsp;''n''}} for a decimal significand ''m'' and integer exponent ''n'' means the same as {{nowrap|''m'' × 10<sup>''n''</sup>}}. For example [[Avogadro constant|{{val|6.022E23}}]] is written as {{code|6.022E23}} or {{code|6.022e23}}, and [[Planck length|{{val|1.6E-35}}]] is written as {{code|1.6E-35}} or {{code|1.6e-35}}. While common in computer output, this abbreviated version of scientific notation is discouraged for published documents by some style guides.<ref name="Edwards_2009"/><ref>{{Cite book |url=https://www.worldcat.org/title/ocm62872860 |title=The ACS style guide: effective communication of scientific information |date=2006 |publisher=American Chemical Society; Oxford University Press |isbn=978-0-8412-3999-9 |editor-last=Coghill |editor-first=Anne M. |edition=3rd |location=Washington, DC : Oxford; New York |pages=210 |oclc=ocm62872860 |editor-last2=Garson |editor-first2=Lorrin R. |editor-last3=American Chemical Society}}</ref>

Most popular programming languages – including [[Fortran]], [[C (programming language)|C]]/[[C++]], [[Python (programming language)|Python]], and [[JavaScript]] – use this "E" notation, which comes from Fortran and was present in the first version released for the [[IBM 704]] in 1956.<ref name="Fortran"/> The E&nbsp;notation was already used by the developers of [[SHARE Operating System]] (SOS) for the [[IBM 709]] in 1958.<ref name="DiGri-King_1958"/><!-- Not necessarily the first use, but an early one. --> Later versions of Fortran (at least since [[FORTRAN IV]] as of 1961<!-- Possibly also by some versions of FORTRAN II and III. -->) also use "D" to signify [[double precision]] numbers in scientific notation,<ref name="UH-Manoa"/> and newer Fortran compilers use "Q" to signify [[quadruple precision]].<ref name=FortranQ/> The [[MATLAB]] programming language supports the use of either "E" or "D".

The [[ALGOL|ALGOL 60]] (1960) programming language uses a subscript ten "<sub>10</sub>" character instead of the letter "E", for example: <code class=nowrap>6.022<sub>10</sub>23</code>.<ref name="Naur_1960"/><ref name="Savard_2005"/> This presented a challenge for computer systems which did not provide such a character, so [[ALGOL W]] (1966) replaced the symbol by a single quote, e.g. <code>6.022'+23</code>,<ref name="Bauer-Becker-Graham_1968"/> and some Soviet ALGOL variants allowed the use of the Cyrillic letter "[[Yu (Cyrillic)|ю]]", e.g. {{code|6.022ю+23}}{{Citation needed|date=December 2024}}. Subsequently, the [[ALGOL 68]] programming language provided a choice of characters: {{code|E}}, {{code|e}}, {{code|\}}, {{code|⊥}}, or <code><sub>10</sub></code>.<ref name="Algol_1973"/> The ALGOL "<sub>10</sub>" character was included in the Soviet [[GOST 10859]] text encoding (1964), and was added to [[Unicode]] 5.2 (2009) as {{unichar|23E8|DECIMAL EXPONENT SYMBOL}}.<ref name="Unicode"/>

Some programming languages use other symbols. For instance, [[Simula]] uses {{code|&}} (or {{code|&&}} for [[Double precision|long]]), as in {{code|class=nowrap|6.022&23}}.<ref name="SIMULA_1986"/> [[Mathematica]] supports the shorthand notation {{code|class=nowrap|6.022*^23}} (reserving the letter {{code|E}} for the [[e (mathematical constant)|mathematical constant ''e'']]).

{{anchor|Decapower|D notation}}
[[Image:Avogadro's number in e notation.jpg|thumb|upright=1|A [[Texas Instruments]] [[TI-84 Plus series|TI-84 Plus]] calculator display showing the [[Avogadro constant]] to three significant figures in E notation]]

The first [[pocket calculator]]s supporting scientific notation appeared in 1972.<ref name="TI_1973_SR-10"/> To enter numbers in scientific notation calculators include a button labeled "EXP" or "×10<sup>''x''</sup>", among other variants. The displays of pocket calculators of the 1970s did not display an explicit symbol between significand and exponent; instead, one or more digits were left blank (e.g. <code>6.022 23</code>, as seen in the [[HP-25]]), or a pair of smaller and slightly raised digits were reserved for the exponent (e.g. <code>6.022 <sup>23</sup></code>, as seen in the [[Commodore International|Commodore PR100]]). In 1976, [[Hewlett-Packard]] calculator user Jim Davidson coined the term ''decapower'' for the scientific-notation exponent to distinguish it from "normal" exponents, and suggested the letter "D" as a separator between significand and exponent in typewritten numbers (for example, {{code|6.022D23}}); these gained some currency in the programmable calculator user community.<ref name="Decapower"/> The letters "E" or "D" were used as a scientific-notation separator by [[Sharp Corporation|Sharp]] [[pocket computer]]s released between 1987 and 1995, "E" used for 10-digit numbers and "D" used for 20-digit double-precision numbers.<ref name="Sharp"/> The [[Texas Instruments]] [[TI-83 series|TI-83]] and [[TI-84 Plus series|TI-84]] series of calculators (1996–present) use a [[small caps|small capital]] <code><small>E</small></code> for the separator.<ref name="TI-83"/>

In 1962, Ronald O. Whitaker of Rowco Engineering Co. proposed a power-of-ten system nomenclature where the exponent would be circled, e.g. 6.022&nbsp;×&nbsp;10<sup>3</sup> would be written as "6.022③".<ref name="Whitaker_1962"/>