Normalized number: Difference between revisions
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Undid revision 1208850579 by 86.27.248.11 (talk) First, not all rational numbers can be written with a finite number of digits in some basis. Moreover, including an infinite number of digits for normalized numbers may be useful from a theoretical point of view (e.g. for math proofs or specifications). |
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{{Confused|Normal number}}
In [[applied mathematics]], a number is '''normalized''' when it is written in [[scientific notation]] with one
:<math>\pm d_0 .
where ''n'' is an [[integer]], <math>d_0,</math> <math>d_1,</math> <math>d_2</math>, <math>d_3</math>... are the [[Numerical digit|digits]] of the number in base 10, and <math>d_0</math> is not zero. That is, its leading digit (i.e. leftmost) is not zero and is followed by the decimal point. This is the form of [[scientific notation]]. An alternative style is to have the first non-zero digit ''after'' the decimal point. ▼
▲where ''n'' is an [[integer]], <math display="inline">d_0,
==Examples==
As examples, the number
:<math>9.18082 \
while the number
:<math>-5.74012 \times 10^{-3}.</math>
Clearly, any non-zero real number can be normalized.
==Other bases==
The same definition holds if the number is represented in another [[radix]] (that is, base of enumeration), rather than base 10.
In base ''b'' a normalized number will have the form
:<math>\pm d_0 .
where again <math display="inline">d_0 \neq 0,</math> and the digits, <math display="inline">d_0, d_1, d_2, d_3, \ldots,</math> are integers between <math>0</math> and <math>b - 1</math>.
==See also==
*[[Significand]]
▲Converting a number to base two and normalizing it are the first steps in storing a real number as a binary [[floating-point number]] in a computer, though bases of eight and sixteen are also used. Although the point is described as "floating", for a normalised floating point number its position is fixed, the movement being reflected in the different values of the power.
*[[Normal number (computing)]]
==References==
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Latest revision as of 09:16, 19 February 2024
In applied mathematics, a number is normalized when it is written in scientific notation with one non-zero decimal digit before the decimal point.[1] Thus, a real number, when written out in normalized scientific notation, is as follows:
where n is an integer, are the digits of the number in base 10, and is not zero. That is, its leading digit (i.e., leftmost) is not zero and is followed by the decimal point. Simply speaking, a number is normalized when it is written in the form of a × 10n where 1 ≤ |a| < 10 without leading zeros in a. This is the standard form of scientific notation. An alternative style is to have the first non-zero digit after the decimal point.
Examples[edit]
As examples, the number 918.082 in normalized form is
while the number −0.00574012 in normalized form is
Clearly, any non-zero real number can be normalized.
Other bases[edit]
The same definition holds if the number is represented in another radix (that is, base of enumeration), rather than base 10.
In base b a normalized number will have the form
where again and the digits, are integers between and .
In many computer systems, binary floating-point numbers are represented internally using this normalized form for their representations; for details, see normal number (computing). Although the point is described as floating, for a normalized floating-point number, its position is fixed, the movement being reflected in the different values of the power.
See also[edit]
References[edit]
- ^ Fleisch, Daniel; Kregenow, Julia (2013), A Student's Guide to the Mathematics of Astronomy, Cambridge University Press, p. 35, Bibcode:2013sgma.book.....F, ISBN 9781107292550.