Editing Significand (section)

{{short description|Part of a number in scientific notation}}
{{use dmy dates|date=July 2020|cs1-dates=y}}
The '''significand'''<ref name="Kahan_2002"/> (also '''coefficient''',<ref name="Kahan_2002"/> sometimes '''argument''',<ref>{{Cite book |last=Clements |first=Alan |url=https://books.google.com/books?id=wUecAQAAQBAJ |title=Principles of Computer Hardware |date=2006-02-09 |publisher=OUP Oxford |isbn=978-0-19-927313-3 |language=en}}</ref> or more ambiguously '''mantissa''',<ref name="Gosling_1980"/> '''fraction''',<ref name="EE_1961"/><ref name="Savard_2005"/><ref group="nb" name="NB_Fraction"/> or '''characteristic'''<ref name="Knuth_ACP"/><ref name="Gosling_1980"/>) is the first (left) part of a number in [[scientific notation]] or related concepts in [[Floating-point arithmetic|floating-point]] representation, consisting of its [[significant digit]]s. For negative numbers, it does not include the initial minus sign.

Depending on the interpretation of the [[exponent]], the significand may represent an [[integer]] or a [[fractional number]], which may cause the term "mantissa" to be misleading, since [[Mantissa (logarithm)|the ''mantissa'' of a logarithm]] is always its fractional part.<ref>{{Cite book |last=Magazines |first=Hearst |url=https://books.google.com/books?id=Ad4DAAAAMBAJ&pg=PA291 |title=Popular Mechanics |date=February 1913 |publisher=Hearst Magazines |pages=291 |language=en}}</ref><ref>{{Cite book |last=Gupta |first=Dr Alok |url=https://books.google.com/books?id=IVTvDwAAQBAJ |title=Business Mathematics by Alok Gupta: SBPD Publications |date=2020-07-04 |publisher=SBPD publications |isbn=978-93-86908-16-2 |pages=140 |language=en}}</ref> Although the other names mentioned are common, ''significand'' is the word used by [[IEEE 754]], an important technical standard for floating-point arithmetic.<ref>{{Cite book |publisher=IEEE |title=754-1985 - IEEE Standard for Binary Floating-Point Arithmetic|doi=10.1109/IEEESTD.1985.82928 |isbn=0-7381-1165-1 }}</ref> In [[mathematics]], the term "argument" may also be ambiguous, since "the argument of a number" sometimes refers to the length of a circular arc from [[1]] to a number on the [[unit circle]] in the [[complex plane]].<ref>{{Cite book |last1=Gowers |first1=Timothy |url=https://books.google.com/books?id=ZOfUsvemJDMC |title=The Princeton Companion to Mathematics |last2=Barrow-Green |first2=June |last3=Leader |first3=Imre |date=2010-07-18 |publisher=Princeton University Press |isbn=978-1-4008-3039-8 |pages=201 |language=en}}</ref>