Editing Engineering notation (section)

==Overview==
{{uncited section|date=February 2024}}
Compared to normalized scientific notation, one disadvantage of using SI prefixes and engineering notation is that [[significant figure]]s are not always readily apparent when the smallest significant digit or digits are 0. For example, 500&nbsp;μm and {{val|500E-6|u=m}} cannot express the [[uncertainty]] distinctions between {{val|5E-4|u=m}}, {{val|5.0E-4|u=m}}, and {{val|5.00E-4|u=m}}. This can be solved by changing the range of the coefficient in front of the power from the common 1–1000 to 0.001–1.0. In some cases this may be suitable; in others it may be impractical. In the previous example, 0.5&nbsp;mm, 0.50&nbsp;mm, or 0.500&nbsp;mm would have been used to show uncertainty and significant figures. It is also common to state the precision explicitly, such as "{{gaps|47&nbsp;kΩ|±|5%}}"

Another example: when the [[speed of light]] (exactly {{val|299792458|u=m/s}}<ref name="CUU_2014_c"/> by the definition of the meter) is expressed as {{val|3.00E8|u=m/s}} or {{val|3.00E5|u=km/s}} then it is clear that it is between {{val|299500|u=km/s}} and {{val|300500|u=km/s}}, but when using {{val|300E6|u=m/s}}, or {{val|300E3|u=km/s}}, {{val|300000|u=km/s}}, or the unusual but short {{val|300|u=Mm/s}}, this is not clear. A possibility is using {{val|0.300E9|u=m/s}} or {{val|0.300|u=Gm/s}}.

On the other hand, engineering notation allows the numbers to explicitly match their corresponding SI prefixes, which facilitates reading and oral communication. For example, {{val|12.5E-9|u=m}} can be read as "twelve-point-five nanometers" (10<sup>−9</sup> being ''nano'') and written as 12.5&nbsp;nm, while its scientific notation equivalent {{val|1.25E-8|u=m}} would likely be read out as "one-point-two-five times ten-to-the-negative-eight meters".

Engineering notation, like scientific notation generally, can use the [[E notation]], such that {{val|3.0E-9}} can be written as 3.0E−9 or 3.0e−9. The E (or e) should not be confused with the [[E (mathematical constant)|Euler's number e]] or the symbol for the [[Exa-|exa]]-prefix.

:{| class="wikitable" style="padding:0; text-align:center; width:0"
! colspan="5" | [[SI prefix]]es
|-
!style="text-align:center" colspan="2" | Prefix
!style="text-align:center" colspan="3" | Representations
|-
! style="text-align:center" | Name
! style="text-align:center" | Symbol
! style="text-align:center" | Base 1000
! style="text-align:center" | Base 10
! style="text-align:center" | Value
|-
| [[quetta-|quetta]]
| Q
| style="text-align:left;" | 1000<sup>10</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#1030|10<sup>30</sup>]]
| style="text-align:right;" | {{val|1000000000000000000000000000000}}
|-
| [[ronna-|ronna]]
| R
| style="text-align:left;" | 1000<sup>9</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#1027|10<sup>27</sup>]]
| style="text-align:right;" | {{val|1000000000000000000000000000}}
|-
| [[yotta-|yotta]]
| Y
| style="text-align:left;" | 1000<sup>8</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#1024|10<sup>24</sup>]]
| style="text-align:right;" | {{val|1000000000000000000000000}}
|-
| [[zetta-|zetta]]
| Z
| style="text-align:left;" | 1000<sup>7</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#1021|10<sup>21</sup>]]
| style="text-align:right;" | {{val|1000000000000000000000}}
|-
| [[exa-|exa]]
| E
| style="text-align:left;" | 1000<sup>6</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#1018|10<sup>18</sup>]]
| style="text-align:right;" | {{val|1000000000000000000}}
|-
| [[peta-|peta]]
| P
| style="text-align:left;" | 1000<sup>5</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#1015|10<sup>15</sup>]]
| style="text-align:right;" | {{val|1000000000000000}}
|-
| [[tera-|tera]]
| T
| style="text-align:left;" | 1000<sup>4</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#1012|10<sup>12</sup>]]
| style="text-align:right;" | {{val|1000000000000}}
|-
| [[giga-|giga]]
| G
| style="text-align:left;" | 1000<sup>3</sup>
| style="text-align:left;" | &nbsp;[[1000000000 (number)|10<sup>9</sup>]]
| style="text-align:right;" |{{val|1000000000}}
|-
| [[mega-|mega]]
| M
| style="text-align:left;" | 1000<sup>2</sup>
| style="text-align:left;" | &nbsp;[[1000000 (number)|10<sup>6</sup>]]
| style="text-align:right;" | {{val|1000000}}
|-
| [[kilo-|kilo]]
| k
| style="text-align:left;" | 1000<sup>1</sup>
| style="text-align:left;" | &nbsp;[[1000 (number)|10<sup>3</sup>]]
| style="text-align:right;" | {{val|1000|fmt=gaps}}
|- style="background-color:#EEE"
| colspan="2" | 
| style="text-align:left;" | 1000<sup>0</sup>
| style="text-align:left;" | &nbsp;[[1 (number)|10<sup>0</sup>]]
| style="text-align:center;" | 1
|-
| [[milli-|milli]]
| m
| style="text-align:left;" | 1000<sup>−1</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#10.E2.88.923|10<sup>−3</sup>]]
| style="text-align:left;" | {{val|0.001}}
|-
| [[micro-|micro]]
| μ
| style="text-align:left;" | 1000<sup>−2</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#10.E2.88.926|10<sup>−6</sup>]]
| style="text-align:left;" | {{val|0.000001}}
|-
| [[nano-|nano]]
| n
| style="text-align:left;" | 1000<sup>−3</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#10.E2.88.929|10<sup>−9</sup>]]
| style="text-align:left;" | {{val|0.000000001}}
|-
| [[pico-|pico]]
| p
| style="text-align:left;" | 1000<sup>−4</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#10.E2.88.9212|10<sup>−12</sup>]]
| style="text-align:left;" | {{val|0.000000000001}}
|-
| [[femto-|femto]]
| f
| style="text-align:left;" | 1000<sup>−5</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#10.E2.88.9215|10<sup>−15</sup>]]
| style="text-align:left;" | {{val|0.000000000000001}}
|-
| [[atto-|atto]]
| a
| style="text-align:left;" | 1000<sup>−6</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#10.E2.88.9218|10<sup>−18</sup>]]
| style="text-align:left;" | {{val|0.000000000000000001}}
|-
| [[zepto-|zepto]]
| z
| style="text-align:left;" | 1000<sup>−7</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#10.E2.88.9221|10<sup>−21</sup>]]
| style="text-align:left;" | {{val|0.000000000000000000001}}
|-
| [[yocto-|yocto]]
| y
| style="text-align:left;" | 1000<sup>−8</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#10.E2.88.9224|10<sup>−24</sup>]]&nbsp;
| style="text-align:left;" | {{val|0.000000000000000000000001}}
|-
| [[ronto-|ronto]]
| r
| style="text-align:left;" | 1000<sup>−9</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#10.E2.88.9227|10<sup>−27</sup>]]&nbsp;
| style="text-align:left;" | {{val|0.000000000000000000000000001}}
|-
| [[quecto-|quecto]]
| q
| style="text-align:left;" | 1000<sup>−10</sup>
| style="text-align:left;" | &nbsp;[[Orders of magnitude (numbers)#10−30|10<sup>−30</sup>]]&nbsp;
| style="text-align:left;" | {{val|0.000000000000000000000000000001}}
|}