¶ This is the Chaptur{e} of duplacioɳ, in þe quych craft þ{o}u most haue & know 4 thing{es}. ¶ Þe first þ{a}t þ{o}u most know is what is duplacioɳ. þe secu{n}de is how mony rewes of fig{ur}es þ{o}u most haue to þis craft. ¶ þe thryde is how many cases may[{6}] happe in þis craft. ¶ þe fourte is what is þe p{ro}fet of þe craft. ¶ As for þe first. duplacioɳ is a doublyng{e} of a nombre. ¶ As for þe secu{n}de þ{o}u most [*leaf 146b] haue on nombre or on rewe of figures, the quych called nu{merus} dupland{us}. As for þe thrid þ{o}u most know þat 3 diu{er}se cases may hap in þis craft. As for þe fourte. qwat is þe p{ro}fet of þis craft, & þ{a}t is to know what a-risyȝt of a nombre I-doublyde. ¶ fforþ{er}-mor{e}, þ{o}u most know & take gode hede in quych side þ{o}u schall{e} be-gyn in þis craft, or ellis þ{o}u mayst spyl all{e} þ{i} lab{er} þ{er}e aboute. c{er}teyn þ{o}u schalt begyɳ in the lyft side in þis Craft. thenke wel ou{er} þis verse. ¶ [{7}]A leua dupla, diuide, m{u}ltiplica.[{7}] [[Subt{ra}has a{u}t addis a dext{ri}s {ve}l medi{a}b{is}]] The sentens of þes verses afor{e}, as þ{o}u may see if þ{o}u take hede. As þe text of þis verse, þat is to say, ¶ Si vis duplare. þis is þe sentence. ¶ If þ{o}u wel double a nombre þus þ{o}u most be-gynɳ. Write a rewe of figures of what nomb{re} þou welt. v{er}sus. Postea p{ro}cedas p{ri}ma{m} duplando figura{m} Inde q{uo}d excrescit scribas vbi iusserit ordo Iuxta p{re}cepta tibi que dant{ur} in addic{i}one. [Sidenote: How to work a sum.] ¶ Her{e} he telles how þ{o}u schalt worch in þis Craft. he says, fyrst, whan þ{o}u hast writen þe nombre þ{o}u schalt be-gyn at þe first figur{e} in the lyft side, & doubull{e} þat fig{ur}e, & þe nombre þat comes þ{ere}-of þ{o}u schalt write as þ{o}u diddyst in addicioɳ, as ¶ I schal telle þe in þe case. v{er}sus. [Headnote: The Cases of the Craft of Duplation.] [*leaf 147a] ¶ Nam si sit digitus in primo limite scribas. [Sidenote: If the answer is a digit, write it in the place of the top figure.] ¶ Her{e} is þe first case of þis craft, þe quych is þis. yf of duplacioɳ of a figur{e} arise a digit. what schal þ{o}u do. þus þ{o}u schal do. do away þe fig{ur}e þat was doublede, & sett þ{ere} þe diget þat comes of þe duplacioɳ, as þus. 23. double 2, & þ{a}t wel be 4. do away þe figur{e} of 2 & sett þ{ere} a figur{e} of 4, & so worch forth till{e} þ{o}u come to þe ende. v{er}sus. ¶ Articul{us} si sit, in p{ri}mo limite cifram, ¶ Articulu{m} v{er}o reliquis inscribe figuris; ¶ Vel p{er} se scribas, si nulla figura sequat{ur}. [Sidenote: If it is an article, put a cipher in the place, and ‘carry’ the tens. If there is no figure to ‘carry’ them to, write them down.]