Editing Inch (section)

===Technical details===

The international standard symbol for inch is '''in''' (see [[ISO 31-1]], Annex A) but traditionally the inch is denoted by a [[Prime (symbol)|double prime]], which is often approximated by a [[quotation mark|double quote]] symbol, and the [[Foot (unit)|foot]] by a [[Prime (symbol)|prime]], which is often approximated by an [[apostrophe (mark)|apostrophe]]. For example; ''{{nowrap|three feet, two inches}}'' can be written as 3{{prime}} 2{{pprime}}. (This is akin to how the [[minute|first]] and [[second]] "cuts" of the [[hour]] are likewise indicated by prime and double prime symbols, and also the [[Minute of arc|first]] and [[Second of arc|second]] cuts of the [[Degree (angle)|degree]].)

Subdivisions of an inch are typically written using [[dyadic rational|dyadic fractions]] with odd number numerators; for example, ''{{nowrap|two and three-eighths of an inch}}'' would be written as {{sfrac|2|3|8}}{{pprime}} and not as 2.375{{pprime}} nor as {{sfrac|2|6|16}}{{pprime}}.  However, for engineering purposes fractions are commonly given to three or four places of decimals and have been for many years.<ref>{{cite book|last1=Flatchet|first1=E|last2=Petiet|first2=J|title=The student's guide to the locomotive engine|url=https://archive.org/details/studentsguideto00ptgoog|date=1849|publisher=John Williams and Co|page=xi|quote=One Metre is equal to ... 30.371 inches"}}</ref><ref>{{cite book|last=Parkinson|first=A C |title=Intermediate Engineering Drawing|date=1967|edition=sixth|page=11|quote=The basic major dia is actually 1.309 in.}}</ref>