Engineering Notation

Engineering notation is a version of scientific notation in which the exponent p in expressions of the form a×10^p is chosen to always be divisible by 3. Numbers of forms such as 12×10^(-6), 230×10^(-3), 340, and 4.5×10^3 therefore correspond to engineering notation, while numbers such as 12×10^(-2), 2×10^2, and 123×10^5 do not.

16 of the 20 SI prefixes (excluding centi-, deci-, deka-, and hecto-) correspond to engineering notation.

Engineering notation is sometimes written using "E notation," which represents for example 3.0×10^9 as 3.0E9 or 3.0e-9. Here, the E or e is shorthand for 10^... and should not be confused with the base of the natural logarithm e.

Care must be taken when attempting to infer significant digits from numbers expressed in engineering notation. For example, while 3.0×10^5 unambiguously indicates two significant digits in scientific notation, the number of significant digits in 300×10^3 is not clear, with the only obvious way to indicate significance being to write the number in the awkward form 0.30×10^6.

See also

Expanded Notation, Scientific Notation, SI Prefixes, Significant Digits

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Cite this as:

Weisstein, Eric W. "Engineering Notation." From MathWorld--A Wolfram Web Resource.

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