4 1 5 ", ▁which ▁is ▁ ▁trunc ated ▁to ▁four ▁digits , ▁will ▁discover ▁values ▁of ▁ ▁trunc ated ▁to ▁more ▁than ▁four ▁digits . ▁ ▁History ▁The ▁concept ▁of ▁round ing ▁is ▁very ▁old , ▁perhaps ▁older ▁even ▁than ▁the ▁concept ▁of ▁division . ▁Some ▁ancient ▁cl ay ▁table ts ▁found ▁in ▁Mes op ot am ia ▁contain ▁tables ▁with ▁rounded ▁values ▁of ▁reci pro cal s ▁and ▁square ▁roots ▁in ▁base ▁ 6 0 . ▁R ounded ▁approxim ations ▁to ▁, ▁the ▁length ▁of ▁the ▁year , ▁and ▁the ▁length ▁of ▁the ▁month ▁are ▁also ▁ancient — see ▁base ▁ 6 0 ▁examples . ▁ ▁The ▁round - to - even ▁method ▁has ▁served ▁as ▁the ▁A ST M ▁( E - 2 9 ) ▁standard ▁since ▁ 1 9 4 0 . ▁The ▁origin ▁of ▁the ▁terms ▁un bi ased ▁round ing ▁and ▁stat istic ian ' s ▁round ing ▁are ▁fairly ▁self - ex plan atory . ▁In ▁the ▁ 1 9 0 6 ▁fourth ▁edition ▁of ▁Pro b ability ▁and ▁Theory ▁of ▁Error s ▁Robert ▁Sim pson ▁Wood ward ▁called ▁this ▁" the ▁computer ' s ▁rule " ▁indicating ▁that ▁it ▁was ▁then ▁in ▁common ▁use ▁by ▁human ▁computers ▁who ▁calculated ▁mathematical ▁tables . ▁Church ill ▁Eisen hart ▁indicated ▁the ▁practice ▁was ▁already ▁" well ▁established " ▁in ▁data ▁analysis ▁by ▁the ▁ 1 9 4 0 s . ▁ ▁The ▁origin ▁of ▁the ▁term ▁bank ers ' ▁round ing ▁remains ▁more ▁obsc ure . ▁If ▁this